Spectra Precision Survey Pro CE v3.60 User Manual

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SURVEY PRO

for Windows® CE

GPS User’s Manual

2002 Tripod Data Systems, Inc.

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GPS User’s Manual

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.MAN-CESURVPROGPS 10152002

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Table of Contents

Introduction........................................................................................... 1

GPS Coordinates................................................................................... 2

Datums .......................................................................................2

Horizontal Datums....................................................................................4

Vertical Datums.........................................................................................6

Coordinate Systems..................................................................8

Horizontal Coordinate Systems.............................................................10

Vertical Coordinate Systems..................................................................14

Survey Pro Coordinate System Database.............................................16

GPS Measurements............................................................................17

Pseudo-Range Positioning.....................................................17

Differential GPS.......................................................................................17

Differential GPS with Survey Pro.........................................19

RTK Data Collection..........................................................................21

Setting Projection Mode.........................................................21

Projection Mode Summary.....................................................................22

Mapping Plane Setup..............................................................................24

Selecting Geoid Model ............................................................................27

Using Ellipsoid Heights ..........................................................................28

Receiver Setup.........................................................................28

General Hardware Configuration.........................................................28

Base Station Receiver Setup ...................................................................30

Rover Receiver Setup..............................................................................33

Solve Localization...................................................................34

Localization with Control Points...........................................................35

Localization Parameters Explained.......................................................41

One Point Localizations..........................................................................46

RTK Data Collection...............................................................49

Measure Mode .........................................................................................49

Data Collection Methods........................................................................51

RTK Stake Out.........................................................................55

Bluetooth Communication.....................................................56

Configuring the Bluetooth Settings.......................................................56

Bluetooth Limitations..............................................................................58

Recovering from Signal Loss..................................................................59

iii

GPS User’s Manual

Bluetooth Error Messages ......................................................................59

Projection Utilities..............................................................................61

Projection Calculator ..............................................................61

Scale Factor Calculator ...........................................................................61

Convergence Calculator .........................................................................62

Readjust Points........................................................................62

Geodetic to Plane.....................................................................................62

Plane to Geodetic .....................................................................................63

Managing GPS Coordinates with TDS...........................................66

Survey Pro................................................................................66

Manual Mode...........................................................................................66

Edit Points ................................................................................................67

Import a .GPS File ...................................................................................68

Survey Link..............................................................................69

File Import................................................................................................69

File Export ................................................................................................70

Post Processing Data Collection.......................................................71

Field Procedure .......................................................................71

Turn On Post Processing........................................................................71

Start Recording in Receiver....................................................................72

Data Collection ........................................................................................72

Office Procedure......................................................................74

Tutorial Jobs ........................................................................................75

Trouble Shooting................................................................................87

References............................................................................................91

Introduction

This book is divided into two parts. The first part is the user’s manual. The second part is the reference manual.

The users manual includes a brief explanation of the basic concepts of GPS coordinate systems and GPS measurements. The following sections cover step-by-step instructions on how to use Survey Pro GPS for RTK and post processing data collection. At the end of the user's manual are some tutorial jobs you can do to illustrate the instructions in the book.

The reference manual contains descriptions and illustrations of every Survey Pro GPS screen. The reference ma nual is divided into sections based on the S u rvey Pro GPS menus. To find the description of a particular screen, simply refer to the section dealing with that menu and screen.

GPS Coordinates

To represent positions in space you need two things. First, you need a datum to define an origin, an orientation, and a scale. Second, you need a coordinate system to specify the locations in the datum. GPS positions are in a global geocentric datum, us ing latitude and longitude angles to specify location. Most engineering and surveying jobs require positions in a 2D Cartesian coordinate system. In order to use GPS with most coordinate systems, we must transform the GPS measurements into local coordinates.

Some jobs require a coordinate system based on a specified mapping plane and geodetic datum, such as a UTM. For this case, the section below describes how Survey Pro converts WGS84 GPS positions into local north and east coordinates. Other jobs have an arbitrary coordinate system, such as a re-survey of an old conventional traverse or starting a new job from scratch. For this case, you can use TDS Localization, and you will not need to know the details of anything in this section.

Datums

A datum consists of three components: an origin, an orientation, and a scale. The origin defines the start point, the orientation defines the direction of the bearings, and the scale defines the relative magnitude of the distance units. For example, a surveyor shows up at a new job site, places a monument in the ground and calls it (5000, 5000, 100). This establishes the origin of the datum. The surveyor does a sun shot and calculates the azimuth to a reference object. Astronomic north at this meridian establishes the orientati on of the datum. Finally, the surveyor begins measuring distances with a total station. The EDM establishes the scale of th e datum.

GPS measurements are taken in a global geocentric da tum, the World Geodetic System of 1984 (WGS84). The WGS84 datum has its origin at the earth’s center of mass, its orientation defined by the earth’s spin axis and the int ersection of the mean meridian of Greenwich with the mean equatorial plane, and its scale defined by metric standard measurement.

GPS Coordinates

Geocentric datums such as WGS84 use a rotational ellipsoid to model the shape of the earth. The WGS84 ellipsoid was based on and is virtually identical to the Geodetic Reference System of 1980 (GRS80) ellipsoid. The ellipsoid origin is at the earth’s center of mass. Its minor axis corresponds with the earth’s rotation axis and its major axis corresponds to the mean equatorial plane.

WGS84 Geodetic v. Local Geodetic

When the coordinate system i s a mapping plane in a datum ot her than WGS84, positions measured in WGS84 latitude, longitude and height, must be transformed into local latitude, longitude, and height before they can be used to calculate nort hing and easting with the specified map projection.

There are three methods of datum transformation supported by Survey Pro.

• Molodensky Transformation: Is the most commonly used transformation. Three parameters specify an X,Y,Z s h ift between WGS84 and the local datum origin. Survey Pro uses the Molodensky datum transformation algorithms specified in the National Imagery and Mapping Agency T echnical Report

8350.2.1.

• Similarity Transformation: The most precise method of datum transformation. The seven-parameter similarity transformation, also called the Helmert transformation, uses a shift of XYZ origin, a rotation about XYZ axes, and a scale to transform from WGS84 and the local datum.

• Grid File Datum Transformation: Is used when the datum differences are not consistent over large areas. A grid file datum transform uses a data set of shift values. For any location, an approximate shift can be calculated by interpolating from the data set.

For many surveying applications, the horizontal and vertical datums are separate. This is because GPS heights are measured on the ellipsoid with its origin at the earth's center of mass, while elevation is a function of local gravity field, which is influenced by the unequal distribution of mass in the earth.

http://164.214.2.59/GandG/tr8350_2.html

GPS User’s Manual

Below is a description of some common horizontal and vertical datums used by Survey Pro.

Horizontal Datums

•

NAD27

The North American Datum of 1927 (NAD27) horizontal datum was established in t h e early part of the twentieth century to define a horizontal coordinate system in North America. The datum originated at a central point, Meades Ranch in Kansas. From there, conventional triangulation and trilateration networks radiated outward to establish new monuments in the system. The datum was based on the Clarke 1866 ellipsoid, which was the best fitting ellipsoid for the North American continent at the time.

Survey Pro performs a grid transformation for NAD27 in the United States using the NADCON datum sets in *.DGF (datum grid file) format. Several specific Molodensky datum transformations are also available for other areas in North America.

Note: To use a grid datum, you must have the pair of *.dgf files for latitude and longitude shift the Disk\Geodata directory.

•

NAD83 = WGS84

Later in the twentieth century, satellite and Very Long Baseline Interferometry (VLBI) measurements were a dded to the numerous conventional measurement networks and re-adjusted to define the North American Datum of 1983 (NAD83). NAD83 was created to conform to the new global datum, WGS84, and uses the same reference ellipsoid.

Survey Pro uses no datum transformation for NAD83. Therefore, NAD83 = WGS84 in Survey Pro projection calculations.

•

NAD83 ≠ ITRF WGS84(1996.0 , 1997.0 , …)

Continuing improvements in GPS and VLBI technology as well as increased cooperation among world wide agencies, like the International Earth Rotation Society (IERS), led to a much better solution for the Earth’s center of mass and spin axis. The IERS’s solution is adopted as the International Terrestrial Reference Frame

GPS Coordinates

(ITRF). Because the earth’s center of mass and spin axis drift over time, you will often see the WGS84 datum followed by brackets (1996.0). The date in the brackets indicates the epoch defining the datum.

This is all quite confusing. Fortunately, for most RTK GPS applications, you do not need to worry about these WGS84 differences. The significant part of the datum difference is a shift, and you correct this when you specify the GPS base position. The other part of the datum difference is the small rotation of the axes. These rotations are small enough to ignore except for the most precise first order applications.

If your Survey Pro job requires a local datum in one epoch of WGS84 and the WGS84 datum in a different epoch, you can setup a sevenparameter similarity transformation. For the transformation parameters of any epoch of WGS84 an d for a more detailed description of the simila rity transformation and WGS84, see NGS web site

•

High Accuracy Reference Network (HARN)

In the United States, the bulk of the measurements used to establish NAD83 were conventional. These measurements contain sli ght systematic errors that conflict with GPS measurements, which are more precise over long distances. To address this problem in the U.S.A., in 1988 the National Geodetic Survey (NGS) began to update NAD83 coordinate datums with HARN GPS surveys on a state-bystate basis. These HARN surveys determined small (< 5_cm) corrections to the location of A and B order control monuments across the states.

Survey Pro performs a grid transformation for HARN networks in the United States using the NADCON datum files in *.DGF format.

Note: To use a grid datum, you must have the pair of *.dgf files for latitude and longitude shift the Disk\Geodata directory.

Snay, R. How CORS Positions and Velocities Were Derived.

http://www.ngs.noaa.gov/CORS/Derivation.html

Appendix B.

GPS User’s Manual

•

Custom Datum Transformations

Most North American and international datums are pre programmed into the Survey Pro coordinate system database. If you require a datum not programmed into the database, you can use the Projection Key In Wizard to create a custom Molodensky or similarity datum transformation.

Vertical Datums

GPS satellites orbit the Earth’s center of mass, while objects on the surface of the planet are affected by the force of the local gravity field. Although it is possible to accurately model the orbits of satellites about the Earth’s center of mass, modeling the local gravity field is much more difficult because of the unequal distribution of masses within the earth.

We all know that water flows downhill from a higher elevation to a lower one. However, water will not always flow from a higher ellipsoid height to a lower one. Ellipsoid height is simply the altitude above the reference surface, and may not match the slope of the local gravity field. When surveying with GPS, we need to correct for the local gravity field to convert measured ellipsoid heights (h) into orthometric elevations (H). This is usually done with a geoid model.

Survey Pro can use several different geoid models to convert local ellipsoid heights into elevations in a particular vertical datum. Most geoid models are initially based on the global equipotential surfac e used in the definition of the initial WGS84 datum. Below is a description of some vertical geoid models and datums.

Vertical Datums

•

EGM96

The National Imagery and Mapping Agency publishes the globa l geopotential model EGM96 generate the worldwide 15-minute geoid height grid data file, WW15mGH.grd. This file contains geoid separation values at 15minute intervals for the entire globe and provides a good esti mate of geoid slope corrections.

http://164.214.2.59/GandG/wgs-84/egm96.html

. This geopotential model was used to

GPS Coordinates

•

NGVD29

The first continental height datum in the United States was the National Geodetic Vertical Datum of 1929 (NGVD29). According to the technology of the day, this datum was based on normal gravity, that is, the gravity field at the instrument when it was leveled. Points along the coast were chosen and their elevation above sea level was determined from a network of tide gauges. Spirit level networks were then run across the country and closed on the opposite coast. This datum contained a number of systematic errors including unmodeled local gravity effects and refraction errors. Also, it was later discovered that the “mean sea level” from the Atlantic to the Pacific Oceans was not the same.

•

NAVD88

In an effort to address these errors, the North American Vertical Datum of 1988 (NAVD88) was realized from a single datum point in Rimouski, Quebec. This datum is based on actual gravity, which provides a better representation of true orthometric elevations. The primary consideration in the choice of this datum point was to minimize the recompilation of national mapping products. A side effect of this choice is that the NAVD88 datum and the theoretical level surface used to define GRS80 do not agree. The offset b etween the NAVD88 vertical datum and the ITRF global geopotential model is in the neighborhood of 0.27m

Survey Pro does not require choice of a specific vertical datum. For RTK applications, elevations are solved relative to the base using the vertical localization adjustment. Therefore, the vertical datum is established by the datum of the base elevation.

Milbert D.G. Converting GP S Height into NAVD88 Elevation with the GEOID96 Geoid Height Model

http://www.ngs.noaa.gov/PUBS_LIB/gislis96.html

p. 4

GPS User’s Manual

Coordinate Systems

A coordinate system is a way to describe positions in a datum. Coordinate systems range from simple Cartesian (y,x) or (N,E) positions on a flat plane to complex geodetic lati tudes and longitudes on a reference ellipsoid.

Below is a description of some coordinate systems common in surveying:

•

Northing, Easting, Elevation

Survey projects usually use simple plane coordinates. We assume our local datum models a flat earth, and we calculate coordinat es in a Cartesian syst em where the simple laws of plane t rigonometry apply. When a vertical coordinate is required, most survey projects require orthometric elevations.

•

Lat, Lng, Ht

Geodetic horizontal coordinates are usually expressed as two angles called latitude and longitude (φ, λ). Geodetic vertical coordinates are usually expressed as the distance above the ellipsoid called height. The angles describe a point’s position on the surface of the reference ellipsoid. The height describes the altitude normal to the surface of the reference ellipsoid.

Fig. 1: Ellipsoidal Geodetic

Coordinates

GPS Coordinates

•

ECEF XYZ

Geodetic coordinates are some times given in the Earth Centered Earth Fixed (ECEF) Cartesian coordinate system. This coordinate system has its origin at the Earth’s center of mass, the primary (Z) axis is the earth’s spin axis; the secondary (X) axis is the intersection of the equatorial plane an d the mean meridian of Greenwich; the tertiary (Y) axis is orthogonal in a right handed system. An ECEF XYZ coordinate can be converted into the corresponding lat, lng, ht using standard formulas.

Fig. 2: Earth Centered Earth

Fixed Geodetic Coordinates

For many surveying applications, the horizontal and vertical coordinate systems are separate. Below are descriptions of common horizontal and vertical coordinate systems used in surveying and mapping.

GPS User’s Manual

Horizontal Coordinate Systems

Survey projects use horizontal coordi nates on either a local plane or a map projection. For small projects, you can assume a simple flat earth plane and calculate coordinates directly with measured distances. Use TDS localization mode for this procedure. For large projects, a mapping plane is used to accurately represent the curved surface of the earth on a flat plane and conventionally measured distances need to be scaled to the mapping plane grid.

Map Projections

A map projection uses equations to transform local lat itude and longitude into (y,x) Cartesian coordinates on a flat plane. Map projections attempt to minimize distortions to the following properties

•

A map projection is conformal when local angles are preserved. Conformal maps are important for surveying because, for second order surveys, angles measured on the ground are angles on the map. Meridians (lines of longitude) and parallels (lines of latitude) intersect at right angles and shape is preserved locally. The physical characteristic of conformality is that the scale factor at any point on the map is the same in all directions.

Conformality

•

Distance

A map projection is equidistant when it correctly plots distances from the center of the projection to any other place on the map. Most map projections involve some distortion of scale. Consequently, when converting distances measured on the ground to distances on the grid, a scale factor must be applied.

•

Direction

A map projection is azimuthal when azimuths (angles from a point on a line to another point) are correctly plotted in all directions.

http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html

GPS Coordinates

•

Area

A map projection is equi-areal when it correctly plots areas over the entire map. That is, all mapped areas have the same proportional relationship to the areas on the Earth that they represent.

Common Conformal Map Projections in Surveying

•

Transverse Mercator

The Transverse Mercator (TM) projection results from projecting the ellipsoid onto a cylinder tangent to a central meridian. Scale distortion is maximum from east to west and minimum from north to south, so the TM projection is often used to portray areas with large north-south extent. Distortion of scale, distance, direction and area increase away from the central meridian.

Many national grid systems are based on the TM projection. The Universal Transverse Mercator grid system divides the world into 60 6-degree zones. About half of the U.S. states use a TM projection for their State Plane Coordinate Systems. The British National Grid (BNG) is a TM projection with origin at 49 degrees north lat itude and 2 degrees west longitude.

•

Oblique Mercator

The Oblique Mercator projection is similar to the Transverse Mercator projection; the ellipsoid is projected onto a cylinder. However, instead of the cylinder tangent to the ellipsoid along a meridian, it is tangent to the ellipsoid along any great circle other than the Equator or a meridian. This makes the Oblique Mercator projection appropriate for regions centered along lines, which are neither meridians nor parallels.

The Oblique Mercator projection is used for Alaska State Plane zone 1, which covers the panhandle.

•

Lambert Conformal Conic

The Lambert Conformal Conic projecti on results from projecting a sphere onto a cone tangent at two (or one) parallels of longitude. Scale distortion is maximum from north to south and minimum from east to west, so the Lambert projection is used to map areas of large east-west extent. Distortion of scale, distance, direction and area increase as you move away from the standard parallels.

GPS User’s Manual

Lambert projections are used for about half of the State Plane Coordinate System zones in the USA.

•

Stereographic

The Stereographic projection results from projecting an ellipsoid onto a plane. Directions are true from the center point and distortions in scale, area and shape increase uniformly away from the central point. The stereographic projection is azimuthal.

Because the scale is distorted somewhat uniformly in all directions, stereographic map projections are a good representation of a surveyor’s typical flat earth ground coordinate system. For this reason, the stereographic ma p projection is used by the TDS localization algorithm to convert (lat,lng) into local ground level coordinates. For more information on localization, see page 35.

Scale Factors

When converting distances on a map to distances on the ground, you must correct for two different scale distorti ons. First, the effects of the map projection distortion must be corrected with the mapping plane scale factor. Second, the geometric effect of your height above the reference surface (ellipsoid height) must be corrected with the ellipsoid scale factor. Generally, these two scale factors are multiplied together into the combined scale factor.

Mapping Plane Scale Factor

This scale factor accounts for the distortions caused by the mapping plane equations as they fit a curved surface onto a flat plane. It is a function of the mapping plane equations and its exact value depends on your location on the map. Although the scale factor is computed with differential equations of the map projection, one can vis u alize it in a geometric sense. Consider the following diagrams:

K=1.0 K=1.0

K>1.0

Mapping Plane

Fig. 3: Transverse Mercator Mapping Plane

K<1.0

K=0.9996

Central Meridian

K>1.0

Distance on Ellipsoid

Distance on Map

A side view of the cylinder shows the effect of scale

distortion.

•

Mapping Plane

TDS Localization Stereographic Projection

The scale factor at the start location (usua lly the first GPS base station in a project) is calculated for

Terrain

ground distances at the base height. The scale factor increases more or less uniformly in all directions as you move away from the base. The scale factor does not change appreciable within the range of RTK

Ellipsoid

GPS, so this map projection is an excellent way to

model simple flat earth ground level

Fig. 4: Localization Stereographic Mapping

Plane

coordinate systems.

A side view of the ellipsoid and

stereographic mapping plane show the

scale calculated for ground distances at

the base height.

GPS Coordinates

•

Universal Transverse Mercator Projection

The scale factor at th e central meridian (CM) is 0.9996. The scale factor is 1.0 approximately 170-km east and west of the CM. The scale factor is less than one between the CM and the point of tangency. The scale factor is greater than one beyond the point

of tangency. Therefore, at the central meridian, a geodetic distance of 100m scales into a mapping plane distance of

99.96m.

GPS User’s Manual

Ellipsoid Scale Factor

This scale factor accounts for the height of the ground above the reference surface (the ellipsoid). This scale factor is defined geometrically: Consider the following diagram:

dist dist k

elip

/(R+h) = dist

ground

/dist

elip

ground

= R/ (R+h)

−

elip

= R/(R+h)

)sin1(

Ellipsoid Height, h

Radius of Ellipsoid, R

Fig. 5: Ellipsoid Scale Factor

Combined Scale Factor

Generally, the two scale factors are multiplied together into a combined scale factor. The combined scale factor is then a pplied to grid distances to get ground distances:

dist

= k

grid

* k

elip

= dist

map

ground

* k

Distance on Ground

Distance on Ellipsoid

R+h

Vertical Coordinate Systems

GPS measurements provide ellipsoid heights. Most survey projects require orthometric elevations. To convert heights into elevations, you need to correct for the difference between the surface of the reference ellipsoid and the level surface representing the gravity field.

The procedure to convert heights (h) to elevations (H) involves the use of a geoid model. The geoid is a theoretical surface that approximates mean sea level. If one knows the separation between the reference ellipsoid and the geoid, called the geoid undulation (N), then one can determine orthometric elevations from ellipsoidal heights.

Terrain

Geoid

Ellipsoid

h=H+N

Fig. 6: The Height Equation

GPS Coordinates

Geoid Models in TDS Software

Survey Pro has several geoid models in the coordinate syst em database. All of the geoid models use data files in geoid grid file (*.GGF) format.

Note: To use a geoid model, geoid data files (*.GGF) must be in t he Geodata directory.

• Users in the U.S.A., Mexico, and the Caribbean can use either the

NGS Geoid96 or the NGS Geoid99 models. This coverage includes the continental United States, Alaska, Hawaii, Mexico, and the Caribbean.

• Users in Canada can use the Geodetic Survey Division CGG2000

model. See the GSD web site for available data sets.

• Users anywhere in the world can use the NIMA worldwide 15-

minute geoid height grid data file, WW15mGH.ggf. This file covers the entire globe on a 15’ x 15’ grid.

• Users in Australia can use the AUSGEOID98 data set. This data

set is available in several overlapping sub grid files in the *.GGF format at the TDS web site.

Note: To use any of these geoids with Survey Pro, you need to convert the files from their native format into the *.GGF format. This is done with the Geoid Sub Grid function in survey Link. T h e required NGS and the NIMA geoid model data files are supplied free of charge on the TDS Survey Works CD. The Canadian GSD geoid models are a licensed data set, so you have to contact Natural Resources Canada to obtain the data in the NGS.bin format to use with the Survey Link Geoid Sub Grid extraction utility. The Australian geoid model is available in *.GGF format for download at the TDS web site on the GPS page.6

Go to www.tdsway.com and select Downloads.

GPS User’s Manual

Survey Pro Coordinate System Database

Survey Pro uses a Coordinate System Database file (*.CSD) to store the map projection and datum transformation parameters for many different coordinate systems around the world. Also, horizontal and vertical localization adjustments are stored as site records in the database. Below is a list of the terminology used to describe the different records in the coordinate system database.

• Zone: Is the basic record type. A zone record specifies the type of map projection and its parameters. Most zone records have datum and ellipsoid records, and usually a geoid record, already in the database.

• Site: Is a zone record with a horizontal and/or vertical localization adjustment added. Localizations are usually used to correct GPS positions starting from an autonomous base. They can be computed from control points or from manual input of parameters.

• Zone Group: Is a collection of zone and/or site records used to keep the database organized and user selection easier.

• Datum: Is a type of datum transformation and its parameters. A datum record will always have an ellipsoid record already in the database.

• Ellipsoid: Are the two parameters specifying the ellipsoid of the datum.

• Geoid: Is a geoid model and its associated data file.

GPS Measurements

This section gives a brief explanation of GPS measurements. First, a discussion of the basic theory of differential positioning will familiarize you with different solution types and their expected precision. Next, step-by-step instructions will describe how to configure Survey Pro with GPS receivers to perform either Real Time Kinematic (RTK) GPS or data collection for post processing differential GPS.

Pseudo-Range Positioning

GPS solutions are computed using pseudo-range positioning: Position is determined from multiple pseudo-range measurements to different satellites (or space vehicles SV) at a single measurement epoch. The position of the GPS receiver antenna is computed by intersecting the pseudo-ranges from the known SV position in a manner similar to survey resection. Four SVs are required to determine three position dimensions and time. Posit ion dimensions are computed by the receiver in Earth-Centered, Earth-Fixed X, Y, Z (ECEF XYZ) coordinates.

A pseudo-range solution will be one of two types: autonomous, or differential. A single GPS receiver can compute an autonomous position from ranges to four or more SV. This single receiver position is extremely coarse. One can expect errors in the order of 100-m on a bad day. For this reason, any precise GPS must be performed using differential positioning.

Differential GPS

Differential GPS (DGPS) positioning involves subtracting a combination of ranges measured to various satellites from multiple receivers. When the signals are subtracted, the major error sources cancel each other out. However, becaus e you are computing a difference in ranges, the DGPS measurement solves for a coordinate difference and not a coordinate. To compute a coordinate using a coordinate difference, you must specify a starting point.

GPS User’s Manual

Differential Solutions: Types and Quality

Code Differential

Code differential solutions use the Coarse Acquisition (C/A) navigation code transmitted on the GPS carrier wave. Because the wavelength of the code segment is long (300m), code differential is the least precise differential solution. Accuracies of 1-10 meters are possible with DGPS using C/A code differential positioning.

Carrier Phase Differential

Highly precise coordinate differences can be measured using pseudorange positioning with the carrier signal wave. Because t h e wavelength of the carrier wave is only 19 cm, mm level positioning is possible. When the signal arrives at the antenna, we can measure the fractional part of the ca rrier wave. If we can then calculate the whole number of wavelengths between the SV and the antenna (the ambiguity), we can add it to the fractional part and multiply by the length of one cycle to measure a precise range.

Calculating the exact number of wavelengths uses a complicated least squares process, which is often called ambiguity resolution. The ambiguity resolution will yield either a float or a fixed solution.

•

Fixed Solution

We know the number of wavelengths will be a whole number. Techniques are used to constrain the least squares solution to yield a whole number. If we get an acceptable solution, we say that this solution is fixed. A fixed solution will generate coordinate differences precise to about 15-ppm (si n gle frequency) or 5-ppm (dual frequency), which translates into 15-mm or 5-mm over a 1-km base line.

Several things may prevent you from achieving a fixed solution: bad multi-path, low number of satellites and bad constellation geometry, poor radio link for corrections (RTK).

•

Float Solution

If the constraint algorithm does not produce an acceptable fixed solution, then the ambiguity is allowed to be a decimal (float) number. A float solution will generate coordinate differences precise to about 100 to 500-ppm, which translates into 0.1-m to 0.5-m over a 1-km base line.

GPS Measurements

Differential GPS with Survey Pro

DGPS requires raw data measured from separate receivers to be combined into a single range difference. For Real Time Kinematic (RTK) data collection, the raw data can be broadcast using a radio link or cell phones and the differential solution is solved in real time. For Post Processing data collection, the raw data is collected in each receiver’s internal memory and downloaded to a PC. Then, software is used to combine the raw data and produce the differential solution.

Survey Pro supports three different modes of differential GPS data collection: RTK, Post Processing, and Simultaneous RTK and Post Processing data collection.

Selecting Data Collection Mode

1. Go to Settings from the Job menu.

2. On the Receiver drop down box.

Mode

3. Tap 2..

Note: This switch controls the display of the Survey GPS mode. In RTK mode, the Survey menu contains items to configure a base and rover receiver for RTK data collection. When in RTK mode with post processing turned on, you will get simultaneous post processing data collection every time you occupy a point. In Post Process mode, the survey menu contains items to configure a st atic or a stop and go receiver for post processing data collection.

card, select

RTK

Post Process

in the

menu when in

GPS

GPS User’s Manual

RTK Settings

If you are using Survey Pro for RTK, or RTK and post processing simultaneous data collection, the following cards of the Job, Settings screen contain settings specific to RTK:

• Measure Mode occupations and the type of GPS raw data to store for each point. You can also specify measurement acceptance criteria. For more information see the Reference Manual.

• Projection projection type and specify the path to geodetic data files. For more information see the Reference Manual.

: is where you select the receiver dynamic for point

: is where you set your horizontal and vertical

Post Processing Settings

If you are using Survey Pro for post processing data collection, the following settings apply.

• Post Process by specifying a recording interval for the receiver’s internal memory. You can also specify how to deal with a utonomous positions and select a special layer to store autonomous points on. For more information see the Reference Manual.

: is where you turn on post processing data collection

RTK Data Collection

RTK data collection uses differential GPS corrections broadcast by a base receiver to solve for coordinates at a rover receiver in real time. This section describes how to use Survey Pro for RTK GPS data collection. Topics include:

How to select a projection method

How to configure the base and rover hardware

How to set a base point in the Survey Pro software

How to collect control points and solve the horizontal and

vertical projections How to collect data and stake out measurements

Setting Projection Mode

When you open a new job in Survey Pro, the

Ground - TDS Localization

ground coordinates in any arbitrary coordinate system, such as a resurvey of an old job or a brand new job from a single start point. Using datum or map projection. Survey Pro will automatically initialize a default projection for ground level dist ances when you configure the first RTK base station in the job.

If your job requires a specified map projection and datum from the coordinate system database, then you should switch to projection zone from the database or creates a custom zone and datum transformation using Survey Pro.

In either horizontal projection mode, the user can choose one of two methods for vertical projection:

Heights

vertical coordinate to be orthometric elevations. to use the GPS measured height as the local vertical coordi nate.

Ground - TDS Localization

Mapping Plane

. Use

. In

Localization (+Geoid)

. This is the default mode to produce

, the user does not need to select a

Mapping Plane

mode the user selects a map

Localization (+Geoid)

mode when you want the local

Projection Mode

, or

Use Ellipsoid Heights

is set to

Ellipsoid

GPS User’s Manual

Projection Mode Summary

Horizontal

Ground - TDS Localization

• Local coordinates are at ground level, based on the project height.

• Distances shot with EDM are at ground scale, so are 1:1 with

coordinates solved by the projection.

• Default map projection and datum are automatically initialized with RTK base setup.

Mapping Plane

• Local coordinates are on a conformal map projection grid.

• Distances shot wi th EDM are usually scaled by the combined

scale factor to distances on the map projection grid.

• User selects map projection zone.

Vertical

Localization (+Geoid)

• Vertical coordinate is orthometric elevation.

• User must solve transformation from ellipsoid heights to

elevations. This is done with Localization on control points, or using a geoid model, or a combination of both.

Ellipsoid Heights

• Vertical coordinate is ellipsoid height.

• This mode requires no transformation setup. Use this mode when

vertical coordinates do not need to be elevations.

If you are using projection mode, and you are not using a geoid model, Survey Pro is ready to start the RTK survey upon opening the new job. No projection setup is necessary, so you should move ahead to the next section on Configuring Receivers.

Ground- TDS Localization

for your horizontal

RTK Data Collection

Note: If you are using

projection mode, and you want to use a geoid, you only need to select the geoid model once. Survey Pro remembers the geoid model you last used and will automatically assign this geoid in a new job's Localization map projection zone. You can go directly to Receiver Setup after opening a job.

If you are using a map projection zone and/ or you want to use a geoid, but have never selected one, you will need to choose a zone and/or geoid record from the user interface. The following section describes how to select a map projection and geoid model from the coordinate system database.

1. Go to Projection at the top of the screen to open the Projection card of the Settings

screen. Select the appropriate Horizontal and Vertical Projection Mode and tap OK.

2. If you selected either them up now. Tap Select Zone… on the Horizontal

Select Geoid… on the Vertical card of the Projection screen. You

can also wait and you will be automatically prompted to set them before the first operation th at requires these settings.

Ground- TDS Localization

from the Survey menu. Tap the Settings button

Mapping Plane

for your horizontal

Geoid Model

, you can set

card and

Note: In Mapping Plane mode, when you select a zone record from the coordinate system database, it may have a geoid model attached. If the selected record has a geoid model attached, this record will

become the geoid for the job file and you do not need to tap

*HRLG

separately.

6HOHFW

GPS User’s Manual

Mapping Plane Setup

Use the Mapping Plane Setup screen to either select a map projection zone from one of the zone groups, or select a local ized map projection site from the database. This screen is also used to open the Projection Key In Setup wizard where you can key in the parameters of a custom map projection and datum.

1. Tap

2. To pick a map projection zone from the database, tap

3. If you are picking a map projection z one, select the

4. Select the

5. If you have selected a zone with a datum and a geoid model

6. Tap

6HOHFW =RQH

to open the Mapping Plane Setup screen. in the

Data Base

the database, tap from the drop down list.

attached, the datum and geoid name will be displayed. If you have selected a UTM zone, you must select a down list.

)LQLVK

record.

… on the Horizontal

box. To pick a localized map project ion site from

View Sites

Zone

to set the selected zone or site as the current projection

Site

in the box.

from the drop down list.

card of the Projection screen

View Zones

Zone Group

from the drop

Datum

Note: When you select a zone with no datum, after you tap the datum selected in the drop down list will be added to a copy of the selected zone record and you will be prompted to save the new zone record with a unique name.

• Use the You can only delete user created sites, you cannot delete the original 'system' records in the database.

Note: You cannot undo the deletion of a zone.

'HOHWH

button to delete zones or sites from the database.

)LQLVK

RTK Data Collection

• Use the Key In Parameters button to open the Projection Key In Setup screen where you can configure a custom map projection

and datum.

Projection Key In Setup

Use the Projection Key In Setup screen to create a custom map projection and a custom datum transformation to use as the selected mapping plane zone:

1. Tap Select Zone… on the Horizontal to open the Mapping Plane Setup screen.

2. Tap Key In Parameters > on the Mapping Plane Setup open the Projection Key In Setup screen.

3. Pick the zone types are:

•

4. Pick the datum are:

5. Select the are:

6. Select the projection zone. Choices for grid direction a re:

Zone Type

Transverse Mercator Lambert 1 parallel Lambert 2 parallel Stereographic Oblique Mercator Angle

Datum Type

•

Pick from Data Base

from the coordinate system database.

•

Custom Molodensky

three-parameter datum transformation.

•

Custom Similarity

seven-parameter datum transformation.

Azimuth

•

North Azimuth

grid.

•

South Azimuth

Grid

for the new map projection zone. Supported

(oblique and polar)

for the new map projection zone. Choices for

. Select this choice to use a datum

. Select this choice to enter a custom

type for the new map projection zone. Choices

. Select this choice to have a north azimuth

. This choice to have a south azimuth grid.

direction for positive coordinates in the new map

card of the Projection screen

screen to

GPS User’s Manual

•

North\East Grid

increase positive in the north and east directions.

•

South\West Grid

increase positive in the south and west direct ions.

Note: The geodetic calculation engine and the Survey Pro coordinate geometry engine are separate components. While the geodetic engine can properly handle southwest grid systems, Survey Pro can only operate on a northeast grid system. However, since a southwest grid with a south azimuth is a mirror image of a northeast grid with a north azimuth, Survey Pro can handle this configuration with the following work around: You must set the

Azimuth

north as south and east as west, and the coordinates will be correct for a southwest grid and south azi muth zone.

on the Units

. Select this choice to have coordinates

Azimuth Type to North

card of the Job, Settings screen. You then treat

7. Tap

8. Key in the five or six paramet ers for your new map projection

9. If your zone is Oblique Mercator Angle, the next screen is used to

10. Tap

11. If you selected

12. Tap

13. If you are using a custom datum, enter the datum translations

1H[W

to enter the zone parameters for the new map

projection. zone. pick the

1H[W

on the datum type you specified on the first screen. the list. If you selected either

Similarity Ellipse from Data Base

database, or you can select a custom ellipse.

1H[W

datum, the next screen displays the parameters for the new map projection zone and you can

from WGS84 to Local.

and

Origin

to select the datum. The screen that opens will depend

, then select an ellipse for the new datum. You can select

to open the next screen. If you are using a database

Azimuth

Pick from Data Base

values.

, pick the database

Custom Molodensky

to use an ellipsoid record from the

Key In Ellipse

6WRUH

the record.

to input parameters for

Datum

Custom

from

RTK Data Collection

Note: Note the sign of the datum shift and rotation parameters.

Some datum transformations are given in terms of local datum to WGS84. Survey Pro always assumes datum transformation parameters are WGS84 to local. You might need to reverse the sign of the datum parameters you have to use them in Survey Pro.

14. Tap

15. If you are using a

16. Tap

1H[W

. If you are using a

screen will be the final screen where you can

Custom Similarity

from WGS84 to Local. Also enter the scale, in parts per million from WGS84 to the local datum.

1H[W

to open the final screen where you can review the

parameters for the new map projection zone and where you can

6WRUH

the record to save it in the coordinate system database file.

Custom Molodensky

datum, enter the rotation

datum, the next

6WRUH

the record.

Selecting Geoid Model

Use the Geoid Model Setup screen to select a geoid model and data file to use with either the localization zone or the selected map projection zone. This screen is also used to remove the geoid from the current projection record.

1. Tap Select Geoid… on the Vertical to open the Geoid Model Setup screen.

2. Select a

3. If there are no data files for the selected geoid model, the control will display "No .ggf files for this geoid." If there is only one data file for the selected geoid, the that .GGF file name. If there are multiple data files for the selected geoid, select the geoid you wish to use from the list. When there is a geoid file displayed, the displays the data file name from the .GGF file header.

4. Tap Accept to set the geoid for the current projection record and/or change the data file used by the current geoid model.

• Use the Remove Geoid From Zone button to remove the geoid model from the current projection record.

Geoid Model

to use from the list.

card of the Projection screen

File

control will display

File

File Name

control

GPS User’s Manual

Using Ellipsoid Heights

Ellipsoid height is a method that stores the local ellipsoid height measurement as the vertical coordinate. Use ellipsoid heights if the vertical is not important to the project, or when you intend to transform heights to eleva tions in the office using a s eparate program.

1. Set the card to

2. Tap 2.. Using vertical ellipsoid heights requires no additional projection solution.

Vertical Projection Mode

Ellipsoid Height.

on the Job

, Settings, Projection

Receiver Setup

General Hardware Configuration

1. Connect the power cable or insert the internal battery in to the GPS receiver.

2. Connect the antenna cable.

3. Plug the data collector serial cable into a receiver comm. port.

4. If your receiver does not have an internal radio, plug the radio serial cable into a receiver comm. port. An external radio may need its own power supply. If the radio comm. port does not supply power, plug the radio into external power.

5. Turn the receiver power on.

Battery

Radio

Data Collector

Some systems do not require an external battery.

The baud rates can be different on each serial port.

Fig. 7: General Hardware Configuration

Power Serial Serial GPS Antenna

Receiver

GPS Antenna

6. Plug the data collector into the receiver.

RTK Data Collection

7. Go to the Receiver

5HFHLYHU 6HWWLQJV

Data Collector to Receiver Communications

8. We will automatically attempt to connect to the receiver. If we can not connect to the receiver, you will be prompted to auto

detect the correct baud rate and receiver port. Tap 2. at the prompt or tap

9. If the port and baud rate detected are not appropriate for your receiver, correct them now. If this is not the correct port, then plug the serial cable into the correct port on the receiver and redo

$XWR 'HWHFW

baud and tap

10. Communications is now set. Tap

Format for RTK Corrections

11. Select your the combo box.

Receiver to Radio Communications

12. Select the type of radio modem you are using.

. If this is not the correct baud, then select the correct

Format for RTK Corrections

card from the Job, Settings screen. Tap

&KDQJH

5HFHLYHU 6HW

and then

$XWR 'HWHFW

2.

on the Receiver card.

from one of the choices in

13. Make sure the baud; parity; and port is correct for the radio. On the Base/Rover Radio

correct, tap

14. Depending on your modem type selected, you may be able to configure certain parameters of the modem using Survey Pro.

Tap the screen.

General Settings

15. Set the elevation cutoff. On the General cutoff to be used when you configure the receiver.

&RQILJXUH 6HULDO

&RQILJXUH 0RGHP

card, verify the settings. If settings are not

and set the correct values.

button to open the Radio Settings

card, select the elevation

GPS User’s Manual

16. Set any other parameters specific to your brand and model. On the General available.

17. Hardware configuration is complete. Tap 2. twice to return to the Base Setup screen.

RTK Configurations

Note: The following step is only necessary if you need to use

different COM port settings for your base and rover RTK receivers.

18. Set the base or rover configuration. If this receiver is the RTK base, tap RTK rover, tap automatically set the switch to

configuration

Survey menu, the correct COM port and settings will be set automatically.

card, different receiver brands have special settings

6DYH FXUUHQW UHFHLYHU DV 57. %DVH

6DYH FXUUHQW FRQILJXUDWLRQ DV 57. 5RYHU

Auto Connect RTK with saved

. When you tap

6HW %DVH

. If this receiver is the

6HW 5RYHU

from the RTK

. This will

Base Station Receiver Setup

Use the Base Setup screen to configure a GPS receiver to be an RTK base station and to set the base reference position in Survey Pro.

1. Tap

Pick the Base Point

2. Tap

%DVH 6HWXS

Base screen where information about the current setup is displayed. Tap

6HWXS +5

or vertical height of the antenna.

on the Survey

6HWXS

… to start the Base Setup

to select your antenna type and measure the slant

menu to open the Current GPS

wizard.

RTK Data Collection

Note: If this receiver has already set an antenna with Survey Pro,

the measurement and settings will be recalled from the registry, so you will not have to do this step again.

3. Enter a name for the from the job or you can enter a new point name for the job. If you select:

• An existing point with geodetic coordinates, we send t hese

reference coordinates to the GPS receiver and configure the base coordinate in Survey P ro.

• An existing point with plane only (N,E,Elev) coordinates , we

calculate geodetic coordinates from the current projection, then send this reference position to the GPS receiver and configure the base coordinate in Survey Pro.

• A new point, or, an existing plane point when no projection is

solved, we start from an autonomous position. You will GET an autonomous position from the GPS receiver for your first base setup. You then SET this reference position in the GPS receiver and configure the base coordinate in Survey Pro.

Note: It is strongly recommended that you use only one autonomous GPS base position in a job. If you must use multiple autonomous setups in a single job, you will be prompted to setup and select a separate site record for each setup group.

4. Tap

1H[W

Base Point

. You can select an existing point

Set the Base

The final step of the Base Setup chosen. If the base (lat, lng, ht) is known or can be computed, the final step is to SET the base at the known geodetic position. If the base (lat, lng, ht) is not known, the final step is to GET an autonomous position to SET the base with.

wizard will depend on the base point

GPS User’s Manual

SET Base at Known Geodetic Coordinate

5. Tap

Note: If you have post processing data collection turned on, the receiver will now open a file (with the next available default name), start recording GPS raw data, and enter the station and antenna information for this setup.

6. When done, you will return to the Current GPS Base screen

7. Tap

GET Autonomous Base Position

If you are starting from a new point i n the job, you can GET an autonomous GPS position from the receiver to SET the base reference position and configure the base coordinate in Survey Pro.

8. Tap

9. Check the results displayed in the edit boxes. If it looks good, tap

6(7

to configure the base receiver with this position and

begin broadcasting RTK corrections over the radio link.

where the base stat ion details are displayed.

&ORVH

to return to the Survey

*(7 3RVLWLRQ )URP 5[

receiver. If you wish to get an averaged position, enter a number in

Average position [n] epochs before GET

6(7

to configure the base receiver with this position and begin

broadcasting RTK correcti ons over the radio link.

to get an autonomous position from the

menu.

RTK Data Collection

Rover Receiver Setup

Use the Rover Setup screen to configure a GPS receiver to be an RTK rover.

1. Go to Rover Setup

Rover setup procedure depends on how the base was set. If the base was set with this data collector, the base reference position is already known in Survey Pro and you can simply SET the rover to start your survey. If the base was set with a different data collector, you need to GET the base reference position from the radio link to configure the base coordinate in Survey Pro and start your RTK survey.

SET Rover with Known Base Position

2. Tap

Note: If this receiver has already set an antenna with Survey Pro, the measurement and settings will be recalled from the registry, so you will not have to do this step again.

3. Tap

Note: If you have post processing data collection turned on, the receiver will now open a file (with the next available default name), start recording GPS raw data, and enter the antenna information for this setup.

6HWXS +5

or vertical height of the antenna.

6(7 5RYHU

base information over the radio link.

from the Survey menu.

to select your antenna type and measure the slant

to configure the receiver and begin receiving RTK

4. You will return to the Survey menu when this is complete.

GET Base Position from Radio Link

a. Tap

b. Tap

6HWXS +5

or vertical height of the antenna.

*(7 IURP %DVH

RTK base information over the radio link.

to select your antenna type and measure the slant

to configure the receiver and begin receiving

GPS User’s Manual

c. Note: If you have post processing data collection turned on, the

receiver will now open a file (with the next available default name), start recording GPS raw data, and enter the antenna information for this setup.

d. Once the base station location is received over the radio link, you

are prompted to set the base reference position is Survey Pro. If the base coordinate already exists in your job file, then that point is chosen by Survey Pro as the base point. If the coordinate is new to the job file, then you are prompted to give this new point a name and Survey Pro will create the new base point.

e. The Base Setup

displayed.

f. If your receiver does not support antenna height configuration,

Survey Pro will attempt to calculate the height. You must verify that the values are correct.

g. Tap

h. When done, you will return to the Survey

1H[W!

displayed. Tap position in Survey Pro.

wizard opens with the chosen

and the base position received from the radio link is

6(7

to configure the base station reference

Base Point

menu.

name

Solve Localization

When you start a GPS survey from an autonomous base position, you need to solve a Localization to adjust GPS measurements into local coordinates. This is the case for both horizontal projecti on modes. Using

Ground - TDS Localization

relate your arbitrary GPS start point into your non-geodetic local system. Using a shift the autonomous GPS start point into accurate geodetic coordinates.

In either horizontal mode, the procedure is the same. Starting from an autonomous GPS base setup, you measure GPS positions on control points with know local plane (N,E) coordinates. The parameters for a 2D similarity transformation are calculated with a

Mapping Plane

, you need to solve a localization to

RTK Data Collection

least squares solution using the control points. These parameters are added to the zone record (selected map plane zone or defa ult Localization zone) to create a zone based site record.

Vertical Localizations, with or without a geoid model, uses the same field procedure. Starting from an au tonomous GPS base setup, you measure GPS positions on control points with know l ocal elevations. The vertical adjustment parameters are calculated from the control points. The vertical adjustment will be either a shift to correct geoid elevations to local elevations, or an inclined plane to correct for vertical shift and tilts.

Note: If you are starting a new job in mode, you do not need control points. Simply set the base on your first job file point and solve the projection at the prompt. For a more detailed description of the easiest way to start a new job using Survey Pro, see the section on One P oint Localizations . See Page 46.

Ground - TDS Localization

Localization with Control Points

Horizontal localization is a simple 2D similarity transformation from mapping plane coordinates in an intermediate system to coordinates in your local system. In intermediate system is the default map projection initialized for ground distances at the base height. In intermediate system is the inaccurate map projection calculat ed from the autonomous GPS base.

Vertical localization is a correction from measured ellipsoid heights or geoid elevations calculated from heights, into local elevations. This correction can be a simple shift or a three-parameter inclined plane.

Localization with Control Points: Summary

Select horizontal and vertical projection methods on the

Projection Configure the hardware and set up the base and rover

receivers.

card of the Job, Settings screen.

Ground - TDS Localization

Mapping Plane

mode, the

GPS User’s Manual

Take GPS measurements to a minimum of two horizontal

control points, and either one vertical control point (to calculate shift for geoid model) or three vertical control points (to calculate an inclined plane).

Go to Projection

/RFDOL]DWLRQ «

Select the points to use for horizontal and vertical control and

tap

6ROYH!

from the Survey menu. Tap

6ROYH

Verify solution residual or misclosure quality. Tap

review the parameters and tap Occupy additional local points as check points to verify

solution quality. If desired, additional points can be added as control points and included in solution.

Note: When you resolve the localization, all of your GPS measured points will automatically be recalculated based on the latest solution. Therefore, your local coordinates derived from GPS measurements will always be calculated using the latest solution.

Detailed Procedure

Since the field procedure is the same for both horizontal and vertica l localization solutions, the instructions below cover both cases.

1. After choosing the projection settings (see page 21) and configuring the base and rover receivers (see page 24), go to Control Points

2. Select a control point to occupy and enter the name into the control. Horizontal control points must have a valid northing and easting coordinate in the local system. Vertical control points may have a valid horizontal coordinate (although it is not used in the calculation) but must have a valid elevation.

from the Survey menu.

$FFHSW

to finish setup.

1H[W!

Point

RTK Data Collection

Note: If you select a point from the job’s control file, you will be

prompted to make a local copy of the point. Control point collection will add a geodetic coordinate to the point record and points in the job’s control file cannot be modified.

Note: If

Store GPS Raw

Settings screen is set to

Data on the Measure Mode

EP + Rx Raw

(or + OBN for Ashtech users),

card of the Job,

when you begin a point occupation the control point name is checked as a valid site ID for the receiver. If it is not a valid site ID, we will use a modified point name in th e receiver’s internal file and make a note of the modified name in the job’s .RAW file. The point name in Survey Pro is not changed.

3. Occupy the point and tap

4. When you are happy with the measurement, tap

&RQWURO 3RLQW

to begin data collection.

$FFHSW

5. Check the Results tab for details of th e previous measurement. Check the Map

tab to see the number and position of control

points for this set up group.

6. Collect a minimum of 2 control points to solve horizontal localization. Collect a minimum of three vertical control points to solve vertical localization. Collect one vertical control point to solve just the localization vertical shift when using a geoid model.

7. When you have collected the minimum number of control points, tap

3URMHFWLRQ

to open the Projection

screen.

GPS User’s Manual

8. Tap

Note: If you are using localization for the vertical transform mode, then the next screen will look like the illustration below. If you are using ellipsoid heights, then the vertical column will be missing.

9. In the list box, control points collected

Note: If your base was set up on a known point, that point is an eligible control point. If your base was set up on a new point, then it is not visible on the control point list.

6ROYH /RFDOL]DWLRQ

will be identified with an H and/or V. Points marked H will be used to solve horizontal localization. Points marked with a V will be used to solve vertical localization. You can select or deselect any point by highlig hting that point and then: tap the H and/or V column beside that point; press H and/or V on the keyboard.

to open the Solve Localization

wizard.

10. If you wish to hold the scale of the GPS measurements, but you want the localization adjustment to correct for a rotation, check the

Solve Rotation Only

11. Double check the selection of control points and tap localization parameters are computed using the selected control points, and the next screen is opened with solution RMS values.

12. For both horizontal and vertical, the solution type and RMS value from the control points are displayed. The solution type will be one of:

control in the

Fix H Scale to 1.0

6ROYH !

box.

. The

RTK Data Collection

•

Unique

using less than the minimum number of control points (1 horizontal or 2 vertical). In this case, there is no least squares solution so the numbers in the

N Err, E Err

misclosures calculated from the control points not used in the solution.

: the solution was calculated

, and/or

columns are

V Err

•

and/or solution.

13. If you are not happy with the solution residual or misclosure values for any point, you can change the control points used by

tapping in the H and/or V columns. This will change the button to a

the solution and update the residual / misclosure display.

14. When you are happy with the solution quality, tap review the parameters.

15. Examine the scale and rotation values to verify they are reasonable. See the expla n ation of localization parameters (page

48) to determine what is reasonable.

16. When you are happy with the solution, tap horizontal and/or vertical adjustment. If this is the first localization solved, you will be prompted to name the site record. If you are resolving a localization, the parameters of the existing site will be updated.

columns show residuals for each point used in the

V Err

6ROYH!

button. Tap the

: the solution was calculated with

LSQ

at least the minimum number of control points (2+ horizontal and/or 3+ vertical). In this case the

6ROYH!

button to recalculate

$FFHSW

N Err, E Err

1H[W!

to set the

17. Tap

&ORVH

to return to the Control Points

screen.

GPS User’s Manual

Manual Entry of Parameters

Manual entry of parameters is used when you already know the appropriate horizontal and vertical localization parameters for a site. Use manual entry of parameters to key in the site parameters and set it as the current projection record.

If you already know the scale, rotation, translation, and origin for a horizontal site, or if you know the slope, shift and origin of a vertical site, you can manually set the localization parameters.

1. After receiver setup, go to Projection

2. Tap

3. Enter the

4. Enter the

5. Tap

6. Review the results and tap

6ROYH /RFDOL]DWLRQ

then tap

horizontal system.

adjustment.

entered.

0DQXDO (QWU\!

Scale, Rotation, Translations

Slope N, Slope E, Separation

6ROYH!

to show the horizontal and vertical parameters

to open the Solve Localization

$FFHSW

when you are done.

from the Survey menu.

wizard and

, and

of the

Origin

of the vertical

Origin

RTK Data Collection

Localization Parameters Explained

Before you accept a localization solution, you should evaluate the parameters and the quality of the solution. This section describes the meaning and the expected values for the six horizontal and five vertical localization parameters. Guidelines for the quality and geometry of control points plus the solution redundancy and residuals are also described.

Ground - TDS Localization Mode:

Scale: is the scale difference between the

intermediate mapping plane and the local system. Scale s h ould be very close to 1.0. A value of 1.0 corresponds to ground level distances at the base reference height.

Scale values are often reduced to parts per million in order to relate the factor to a distance. One ppm (the sixth decimal place ie.

1.000001 or 0.999999) is equal to 1mm in 1km; this is well below RTK precision. Fifteen ppm (1.000015 or 0.0.999985) is equal

to 15mm in 1km; this is a usual RTK precision, so anything in this range is expected. A scale value significantly greater or smaller than 1.0 may indicate problems with the control point accuracy and/or the control measurement precision. It might also indicat e a base reference height too high or low for the survey area, or a scale bias in the control point local coordinates.

Rotation: is the rotation between the Localization map projection zone and the local system. The rotation represents th e difference between grid north and geodetic north at the meridian passing through the origin of the Localization transformation.

Origin: is the coordinate on the intermediate mapping plane of the centroid of the control points. It is calculated by average of (N, E) coordinate of all control points.

Translation: is the shift between the origin and the local coordinate of the centroid of the control points

GPS User’s Manual

Mapping Plane Mode: Scale: is the scale difference between t h e intermediate mapping

plane using the autonomous GPS position and the actual mapping plane control coordinates. Scale should be very close to 1.0. A value of 1.0 corresponds to grid distances on the selected conformal mapping plane.

A scale value significantly greater or smaller than 1.0 may indicate problems with the control point accuracy and/or the control measurement precision. It might also indicate a scale bias in the control point plane coordinates, which you may want to correct by solving a fixed scale transformation.

Rotation: will be 0.0 for Localized map projections. Origin: is the coordinate on the intermediate mapping plane of the

centroid of the control points. It is calculated by average of (N, E) coordinate of all control points.

Translation: is the shift between the origin and the local coordinate of the centroid of the control points. This value represents the shift from the inaccurate autonomous GPS start point and the actual coordinates for that position. This value should be less than 15 m with Selective Availability turned off.

Vertical: Slope: is the North and East tilt of the

inclined plane adjustment. These values are given in parts per million, and represent the radian angle values of the deflection between the ellipsoid normal and the local gravity vector. These values ar e also called 'deflection of the vertical'.

Separation: is the shift between the local elevation and the vertical reference surface (geoid elevations when using a geoid model or ellipsoid height when using Localization vertical only).

Origin: is the local coordinate of the first point used in the control point list. The slope values are applied from this point.

RTK Data Collection

Normal to Ellipsoid

Separation

Normal to Geoid

Deflection (a,b)

Fig. 9: Vertical Localization

Three control points calculate a plane to model the deflection and shift

between the geoid and ellipsoid surface.

Vertical Calibration and Geoid Modeling

If you do not use a geoid model, vertical localization will solve for slope and separation using the measured heights and the control elevations. If you do use a geoid model, vertical localization will solve for the separation between the geoid elevation and your control elevation. Geoid elevations are computed from measured heights and geoid undulation using the height equation (see page 14):

h = H + N

Quality of Localization Solution:

Starting from an autonomous GPS base position and solving a Localization with control points is like starting a conventional survey from an unknown setup and solving a resection. The quality of the solution depends on both the precision of the measurements to the control points and the accuracy of the control point coordinates. When solving a Localization with control points, the following guidelines should be followed:

• Quality of control points: the control point coordinates should be

at least as precise as the specified survey requirements.

GPS User’s Manual

• Geometry of control points: the control points should be distributed evenly surrounding the survey area.

Fig. 10: Good Control Point

Geometry

Three control points surround the

project area.

• Check points: after solving for localization parameters with a minimum number of control points, you should occupy an independent checkpoint to verify the solution quality. If you desire, this point can be added as a control point and used for subsequent solutions. If the checkpoint measurement is within the tolerance, this step should not be necessary.

• Redundancy and residuals: After solving localization parameters with more than the minimum number of control points, you should examine the solution residuals. The residuals should be close to the measurement precision of your instrument and the control points.

Fig. 11: Poor Control Point

Geometry

Three control points in one corner of

the project area. Also, for vertical

localization, the three control points

are close to co-linear.

RTK Data Collection

Ground - TDS Localization Explained:

When the horizontal projection mode is default map projection is automatically set up to produce ground coordinates at the base station height. The TDS Localization map projection is an oblique stereographic map projection with the following parameters:

Origin is at the initial base station location

False northing and false easting of 100000.0 m

Scale at the origin of t h e stereographic map projection zone is calculated to produce ground scale distances at the height of the first GPS setup. This projection scale factor is simply the inverse of the ellipsoid scale factor described earlier (see page

12). Origin Scale (k

−

Localization Setup Groups

When you set up different base stations with autonomous positions from a GET, each position is only accurate to +- 30m (+- 10 m with Selective Availability (SA) turned off). Geodetic coordinates measured from your first autonomous base will not be accurately connected to geodetic coordinates from a different autonomous base. Although the localization parameters will accurately transform both sets of data to the local coordinate system, it is not possible to compare the geodetic coordinates from the different sets of data.

map

) = (R+h)/ R

1 2

)sin1(

Ground - TDS Localization

, a

Survey Pro solves this problem by assigning a set up group each time a new autonomous base is set. A set up group is a unique flag attached to each point record generated by GPS. Setup groups are assigned as follows:

When you set a new base point with an autonomous GET, Survey

•

Pro creates a new set up group for this point.

GPS User’s Manual

• When you collect geodetic measurements, each new point is assigned the set up group of the current base station.

• When you set the base on an existing point with geodetic coordinates, the point’s existing set up group is used as the new base station set up group.

• When you set the base on a point with existing plane coordinates and compute geodetic coordinates using the ‘Move Base’ algorithm, the existing base station set up group is used as the new base station set up group.

One Point Localizations

When you open a new job and you want to do a ground level survey starting at the coordinate of the first point, you can do a one-point localization when using Below is a description of the easiest way to setu p a new job projection and start a survey.

1. Open a new job and assign the desired local north, east, and elevation to the first point.

TDS Localization

horizontal projection mode.

2. Set the GPS base receiver up on this point and GET an autonomous position and SET the base.

3. At the projection prompt, choose Localization screen. With your base as the one control point, tap

6ROYH!

4. Review the parameters of the solution.

• Scale factor of 1.0 means coordinates will be at ground level at the base station height. Distances measured with an EDM at this height will be 1:1 with GPS measured coordinates.

• Rotation of 0.0 means that the coordinate system's grid north is equal to geodetic north at the meridian of the initial base. This is equivalent to using a sun shot azimuth as grid bearing through this meridian.

6ROYH 1RZ

to open the Solve

RTK Data Collection

• Delta N and E are the translations between the desired local start coordinate and the origin of the TDS Localization map projection (100000, 100000) m.

5. Tap

$FFHSW

. You are now ready to start data collection.

Localization Calculator

Note: The Localization calculator is used to provide the field procedure for a workflow supported in Survey Pro versions prior to

3.5. This routine is similar to a one-point Localization, except that

rotation is calculated parallel to a selected map projection. The easiest way to start a ground survey is with the one point Localization procedure described above.

1. After choosing the projection settings and configuring the base and rover receivers, go to Projection

2. Tap

Note: The vertical card will be the vertical manual parameter screen described in the previous section.

6ROYH /RFDOL]DWLRQ«

then tap

&DOFXODWRU!

to open the Solve Localization wizard and

from the Survey menu

3. Leave the scale at 1.0. For an explanation of the scale factor or to review the reference height used for ground scale, tap the

6FDOH

button.

4. Calculate the rotation for this setup. Tap the Localization Calculator. If you have not already selected a mapping plane, you will be prompted to do so now.

5. Tap

6ROYH 5RWDWLRQ!

origin in the selected map projection zone.

to calculate rotation for the localization

&DOF 5RWDWLRQ

&DOF

to open

GPS User’s Manual

6. Examine the results. The convergence between the central meridian of the selected map projection zone and the base point.

7. If you set your base up on a known point, then the base station coordinates are already entered into the

Coordinate

parameters. Tap Projection screen.

8. If you set your base up on a new point, you need to tap

2FFXS\ &RQWURO

and opened. You need to select and occupy a single control point.

When you are done, tap screen and the calculated coordinates are returned to the and

fields. Tap

Rotation

fields.

East

$FFHSW

. You will be prompted to make sure your

are correct before the Control Points screen is

Rotation

6ROYH!

to finish setup and return to the

$FFHSW

is the negative of meridian

Base Station Local

to calculate the localization

Scale

to return to the Solve Localization

North

9. Tap

6ROYH!

done. You will be prompted to name the new localization site and save the record in the database.

. Examine the results and tap

$FFHSW

when you are

RTK Data Collection

Once your horizontal and vertical projections are solved, you are ready to collect data. The different measure mode settings and data collection options are described below.

Measure Mode

1. Go to Data Collection from the Survey menu. Tap top of the screen.

2. Select the receiver dynamics.

Static on occupy

point occupations. When in static mode, the receiver assumes no antenna movement and uses advanced averaging techniques to compute the most precise position possible.

Dynamic always

for point occupations.

3. Select how to

Lat, Lng, Ht

each point accepted.

EP + Bl,CV

(dX,dY, dZ) and variance covariance information in the .RAW file.

EP + Bl,CV + Rx Raw

base line and variance covariance information in the .RAW file, and send the station information to the receiver’s internal file for post processing.

EP + Rx Raw

send the station information to the receiver’s internal file for post processing.

Store GPS Raw Data

will set the receiver to ‘static’ mode for

will leave the receiver in ‘dynamic’ mode

will store an EP record in the .RAW file for

will store an EP record, plus the raw base line

will store an EP record, plus the raw

will store an EP record in the .RAW file and

6HWWLQJV

at the

Note: Ashtech users store an Ashtech format .OBN record in a separate file and do not store BL,CV records in the .RAW file.

GPS User’s Manual

Note: Raw data types

only available when

Receiver Dynamics

+ Rx Raw

(and/or

is set to

+ OBN

for Ashtech users) are

Static on occupy

Note: All receivers need to be in static mode to record Rx. Raw, and some receivers always record Rx Raw when in static mode. If the combination of settings you select is not compatible for your receiver, you will be prompted to change the settings..

4. Select the

Fixed RTK only Code, Float, or Fix

filter.

will reject all positions that are not fixed.

will allow you to accept any position

accept autonomous or invalid data.

Note: If you are collecting simultaneous RTK and post processing data, you can accept an autonomous position based on the Job/Settings, Post Process card. If enabled, you will either be prompted to put the autonomous position on a separate layer, or it will automatically be stored on a separate layer.

5. Set the

Acceptance Criteria

is used to check each solution you accept. If the measurement exceeds the criteria, you will be prompted to accept or reject the point. Check this box if you want to enable criteria checking. Enter a maximum value for HRMS, VRMS, and/or PDOP in the fields. Only fields with a non-zero value will be used for criteria checking.

To accept data points automatically using the selected

criteria, check the

Auto Accept

box at the bottom of this

page.

6. Tap 2. to return to the Data Collection

screen.

RTK Data Collection

Data Collection Methods

Data Point

Use this method if you want to occupy points one at a time.

1. Go to Data Collection

from the Survey menu.

2. Enter a point name in the you will be prompted to overwrite or choose the next available point.

Note: If you have Ashtech users), your point name must be a valid Site Id for the receiver model. If your point name is not valid, you will be prompted to change it.

3. Enter a

4. If your antenna height has changed, enter a new value in the

Rover

If your antenna type and measure to method have changed since Rover setup, then tap

5. Tap switched from motion to static (for site occupation begins.

6. The Occupy Data Point coordinate calculated from the measurement. When you are

satisfied with the measurement tap Collection screen

Description

field to update the value in Survey Pro and in the receiver.

3RLQW

Store GPS Raw Data

6HWXS +5

to begin measurement. The receiver dynamics are

screen is updated with the local

field. If this point already exists,

Point

set to

to change and update it.

Static on occupy

$FFHSW

+ Rx Raw

to return to the Data

(or

mode) and a

+ OBN

for

7. Check the Results Check the Map

tab to see the points plotted, as they are stored.

tab for details on the last measurement.

GPS User’s Manual

Offset Point

Use this method if you cannot occupy a point directly, but you can occupy a location close by and provide an azimuth and distance to the point.

1. Go to Data Collection

2. Enter a point name in the you will be prompted to overwrite or choose the next available point.

3. Enter a Description.

4. Tap

Note: You can enter the offset data before or after you occupy the reference point with GPS.

5. Tap

6. Enter the distance from the GPS reference point to the offset

2IIVHW

to open the Offset Shots

2FFXS\ *36

prompted for a point name to store the reference point. The receiver dynamics are switched from motion to static (for

occupy

with the measurement, tap screen.

point. You can enter the distance by ha nd or you can get it from the selected conventional instrument by tapping

mode) and a site occupation begins. When you are happy

from the Survey menu.

field. If this point already exists,

Point

screen.

to occupy the GPS reference point. You will be

Static on

$FFHSW

to return to the Offset Shots

6KRRW /DVHU

Note: You have to switch to conventional mode to configure the laser range finder or total station.

7. Enter the direction (azimuth/bearing) from the reference point to the offset point. You can enter a direction in one of the following ways:

Using the horizontal angle returned from the

conventional instrument if you took a shot.

RTK Data Collection

Occupying a point on line with th e reference point and

the offset point. After you occupy the reference poi n t, tap

'LUHFWLRQ IURP 7ZR 3RLQWV

on line with the reference point and the offset point. When you are done occupying the on line point, you will be prompted for the direction to your offset point.

Entering a value by hand.

8. Tap

9. Store any number of additional offset points from this GPS

6WRUH

to store the point.

reference point. The shot data for each point is recorded in .RAW data. Tap

&ORVH

when you are done storing points.

and then occupy a point

Feature Collection

Use this method if you want to collect multiple points using either a measurement interval or by manually accepting each point. You can select from five different data collection modes.

1. Go to Data Collection

2. Enter a point name in the you will be prompted to overwrite or choose the next available point.

Note: If you have

feature collection will not store base line records because there

Raw,

is no discrete site occupation of each point. Therefore, the point name does not need to be a valid Site Id.

3. Enter a Description.

Note: For continuous data collection (except

descriptions

be stored with the same description, layer, and attr ibutes. When using description, layer, and attributes (if set) after every point.

), once the first point is accepted, all additional points will

Manual: multi descriptions

Store GPS Raw Data

from the Survey menu.

field. If this point already exists,

Point

set to

mode, you will be prompted for

+ Bl,CV

Manual: multi

+ Bl,CV + Rx

GPS User’s Manual

4. Tap

5. If you select a continuous method, you must specify an

)HDWXUH

An explanation of the selected method is displayed at the bottom of the screen. See the reference manual for more information.

appropriate

. On the Feature Collection

Interval

screen, select a

Method

6. Tap

7. When you are ready to begin continuous collection, tap

8. If you are using a continuous int erval,

9. If your mode is

10. If you want to see a list of points stored so far, tap

11. Tap

Note: When doing continuous data collection, if your interval is exceeded, but your acceptance criteria or RMS criteria are not met, then you will be prompted to the measurement to pass. If you choose to will be prompted to

6WDUW

to begin measurements. The Occupy Data Point

displays the local coordinate.

$FFHSW

disappears and

points are stored when the interval is exceeded.

, tap

$FFHSW

Manual

point. If your mode is prompted for a description, layer, an d attributes (if set) for each point.

'RQH

to end feature collection and return to the Data

Collection screen.

Manual: multi descriptions

the point anyway or to

when you want to collect a

, you will be

9LHZ 3RLQWV

the point anyway or to

, and then

Wait

Exit

screen

$FFHSW

Wait

Cancel

for

, you

RTK Data Collection

RTK Stake Out

Stake out with GPS is very similar to stake out with conventional instruments. See th e user’s manual for details on the different staking procedures. Below is a description of the two special features of stakeout with GPS.

!5RYLQJ

1. When you first start any GPS staking screen, measurements are started in the GPS receiver in dynamic (moving) mode. This is necessary as you navigate to the design point, and is indicated on

the screen with the toggle button in the

2. When you arrive at the design point, if you want to take a more precise measurement, you need to switch to This will switch the receiver from motion to static (depending on

your

!2FFXS\LQJ

Receiver Dynamics

setting).

!5RYLQJ

!2FFXS\LQJ

position.

mode.

Note: When card is set to

ROVING

will be prompted for a point name and description. The receiver session will be completed and the measurement stored when you tap

'RQH

. The occupation is not stored in the Survey Pro .RAW file if you

toggle back to

 +] 0RGH

1. When you first start any GPS staking screen, measurements are started in the GPS receiver in one Hz mode. If your receiver supports it, you can switch to five Hz mode by checking this control. This will configure the receiver to calculate positions five times a second and the display will update in near real time.

Note: Five Hz mode is for quick navigation to the point, it does not provide the most precise solution of coordinates. When you switch from roving to occupying, the receiver is automatically switched to one Hz.

Store GPS Raw Data

+ Rx. Raw (

OCCUPYING

ROVING.

and / or

will start a session in the receiver, so you

on the Job/ Settings/ Measure Mode

+OBN

for

Ashtech)

switching from

GPS User’s Manual

Bluetooth Communication

Survey Pro can communicate using a wireless Bluetooth connection. Bluetooth technology uses a short-range radio connection between a Bluetooth-enabled data collector and a Bluetooth-enabled receiver as an alternative to a cable serial port connection.

This section explains how to configure Survey Pro to take advantage of Bluetooth and discusses its limitations.

Configuring the Bluetooth Settings

1. Start Survey Pro for Windows CE and make sure it is set to GPS mode.

2. Set the

• From the Main Menu

• Set Serial Port (GPS Receiver)

• From the Receiver Communication

Note: If a Bluetooth connection has not yet been established, two error messages will appear when you try to access the above screens. (See

Bluetooth Error Messages below) Tap 2. to these messages to continue.

5HFHLYHU &RPPXQLFDWLRQ 6HWWLQJV

in Survey Pro, select

5HFHLYHU

screen, tap

5HFHLYHU 6HWWLQJV«

6HWWLQJV

&KDQJH

%OXHWRRWK

-RE

6HWWLQJV

and tap 2..

RTK Data Collection

3. Open the Microsoft® Bluetooth Device Management applet. This is typically accessed from the Windows® CE.NET Control Panel. It can also be accessed while running Survey Pro in either of the following two ways:

Method 1:

• While running Survey Pro, escape to the W indows® CE.NET operating system by pressing

Ctrl

, [ESC].

• Tap | Bluetooth

6HWWLQJV

icon.

&RQWURO 3DQHO

and then double-tap the

Method 2:

• From the Main Menu

5HFHLYHU

5HFHLYHU 6HWWLQJV«

in Survey Pro, select

&KDQJH

6HWWLQJV

-RE

6HWWLQJV

4. From the Bluetooth Device Management

(QDEOH %OXHWRRWK

;

5. Tap

6FDQ

. This will start a radio scan for all the Bluetooth

checkbox.

screen, check the

devices in the vicinity. Eventually, the GPS receiver and its corresponding serial number should be listed in the

8QWUXVWHG

column. If any other Bluetooth devices are in the area, those will also be listed here.

6. Tap the device that corresponds with your receiver in the

8QWUXVWHG 7UXVWHG

list to select it then tap the

list.

!

button to move it to the

7. Select 1R at the prompt asking if you want to authenticate the device. The receiver should now be listed in the

7UXVWHG

column.

GPS User’s Manual

8. After returning to the Receiver Communication

5HIUHVK

9. Tap 2. to continue.

and the new trusted device will be displayed.

screen, tap

Bluetooth Limitations

Bluetooth can be thought of as a short-range radio link. As with any radio link of this type, communications can be interrupted by a number of reasons, including, but not limited to:

• The operating range between the devices is exceeded. (The Bluetooth range is limited to approximately 10 meters.)

• Another powerful radio signal is broadcast near an active Bluetooth device.

• An object, such as your body, physically blocks the radio signal.

When the Bluetooth radio signal is lost, the results in the software are not predictable and there is potential for a system crash, requiring a hard reset. (See Recovering from Signal Loss, below.)

Because of these limitations, it is suggested that Bluetooth only be used when the following criteria are met:

• Bluetooth should only be used duri ng RTK GPS data collection where constant communication between the Bluetooth devices is least critical.

• Bluetooth should only be used whi le the data collector is physically attached to the rod, which removes the possibility that the range limitation will be exceeded.

Warning: It is not recommended that Bluetooth communication be used during static GPS occupation, or while logging GPS data to use for post processing. Both of th ese scenarios require constant and reliable communications between the data collector and the receiver. In these situations, a cable should be used for communicat ion.

RTK Data Collection

Recovering from Signal Loss

If Bluetooth communications failure occurs and the software is not able to recover, you may need to uncheck and then re-check the

Enable Bluetooth

;

Management screen. This screen is accessed from either of the methods described in Step 3, under Configuring the Bluetooth Settings, above.

checkbox from the Bluetooth Device

Bluetooth Error Messages

Any of the messages displayed here will appear whenever a screen is accessed that looks for a Bluetooth connection and the connection is not established. T h ese errors are normal if the connection has not yet been configured and

established as described above. The last error message shown here will occur

after a Bluetooth connection was established and then is suddenly lost. Tapping 2. will dismiss the dialog and return you to the

current screen without a connection. Tapping

6HWWLQJV

Device Management applet where you can uncheck and re-check the checkbox to reestablish the connection.

will open the Microsoft® Bluetooth

(QDEOH %OXHWRRWK

Projection Utilities

Projection Calculator

You can use the Projection Ca lculator to calculate combined scale factor for scaling conventional distance measurements to the mapping plane. You can also use the Projection Calculator calculate meridian convergence for reducing geodetic azimuths (like a sun shot) to grid bearings.

Scale Factor Calculator

1. Go to Projection Calc ulator from the Survey menu.

2. Choose a point on the mapping plane for scale computation in the

Select Point

control. Tap

6ROYH 6FDOH!

3. Enter a height to compute uses the height of the point above the ellipsoid to correct for the effect of the terrain above the reference surface.

4. Tap

5. Tap

6ROYH!

selected values. The combined scale factor is displayed in the

Ground to Grid

the

Grid to Ground

$FFHSW

Past Results

to calculate the combined scale factor with the

box. The inverse combined factor is displayed in

box.

when you are done. Both numbers are saved in the

list so you can use them in other cal c ulations.

Ellipsoid Scale Factor

. This calculation

GPS User’s Manual

Convergence Calculator

1. Go to Projection Calc ulator from the Survey menu.

2. Choose a point on the mapping plane for convergence computation in the

3. The convergence and rotation are calculated. The convergence is displayed in the displayed in the

Select Point

Geodetic N to Grid N Grid N to Geodetic N

control. Tap

box. The rotation is box.

6ROYH 5RWDWLRQ!

4. Tap

$FFHSW

Past Results

when you are done. Both numbers are saved in the

list so you can use them in other cal c ulations.

Readjust Points

The Readjust Points screen is used to perform transformations from geodetic to plane coordinates and vice versa.

Note: If you resolve a localization adjustment, the plane coordinate of all of the geodetic point records is automatically updated. It is not necessary to use this screen to update job file coordinates with Survey Pro.

Geodetic to Plane

This function recomputes the plane coordinates of the selected points using the geodetic coordinates and the latest projection solution.

1. Go to Readjust Points

from the Survey menu.

2. Select some points to readjust.

3. Tap the specify what to adjust.

Adjust Horizontal

and/or

Adjust Vertical

check boxes to

Projection Utilities

4. Tap

*HRGHWLF WR 3ODQH!

be changed. If you are sure you are ready to proceed, tap 2..

. You will be warned that coordinates will

5. The final page displays the results. The number of points adjusted. If some points were not adjusted, a list of these points and an explanation why th ey were not adjusted is displayed.

Reasons Points are Not Adjusted

• Setup Group Not Compatible: If you selected a point that does not belong to the current set up group, then it is not adjusted. If the set up groups do not match, we cannot be sure the geodetic coordinates are accurate with respect to the current projection solution.

• Geodetic Coordinates Not Valid: If you selected a point without a geodetic coordinate, it is not adjusted. Wit h out geodetic coordinates, we cannot re-calculate a new plane position.

• Control Point: If you have selected a control point it is not adjusted. Control point locations cannot be modified.

Results

box displays the

Plane to Geodetic

This function checks or re-computes geodetic coordinates of the selected points using the plane coordinates and the latest projection solution.

1. Go to Readjust Points

2. Select some points to readjust.

3. Tap the specify what to adjust.

4. Tap to

5. Tap geodetic coordinates. The projection will be applied to the GPS coordinate and the result will be compared to the plane coordinate. This operation does not change coordinate records.

Adjust Horizontal

3ODQH WR *HRGHWLF!

&KHFN!

5HFDOFXODWH!

if you want to compare the plane coordinates to the

from the Survey menu.

and/or

to open the second screen. You can choose

Adjust Vertical

point coordinates.

check boxes to

GPS User’s Manual

5b. Tap

plane coordinates. This action will change point records and you will be prompted to ensure you are ready to proceed.

5HFDOFXODWH!

to generate new GPS coordinates based on the

6. The final screen disp lays the results. The the number of points checked or adjusted. If you checked points, the Results box also displays the horizontal and/or vertical error and if any points were not checked. If you adjusted points, and some points were not adjusted, a list of these points and an explanation is displayed.

Reasons Points are Not Checked or Adjusted

• Coordinates Not Valid: If you selected a point that does not have a valid (northing, easting) and/or elevation coordinate, it is not checked or adjusted.

• No Geodetic Coordinates for Comparison: If you have selected a point without a geodetic coordi nate, it is not checked. Without geodetic coordinates, we cannot re-calculate a comparison plane position.

• Control Point: If you have selected a control point it can be checked, but it cannot be readjusted. Control point locations cannot be modified.

Results

box displays

Changing Projection Definitions

It is highly recommended that you have only one projection definition in a job. This will ensure not only that the local coordinates are all in the same system, but also that the geodeti c coordinates always match the local coordinates using the projection solution. If you have to switch projections in a job , the local coordinates of all the geodetic point records can be computed using Geodetic to Plane. However, this will not adjust plane only coordinates. To readjust all coordinates in a job, use the procedure below.

Projection Utilities

Note: If your projection is a localized site, then any errors in the

localization solution will propagate through to the new coordinate system, possibly degrading precision of the conventionally measured coordinates.

1. Select all job file points, and select to adjust H and V.

2. Tap

3. Re - open the Readjust Points

4. Set the new projection definition.

5. Re-open the Readjust Points

3ODQH WR *HRGHWLF

geodetic to local transformation. Rectify any problem coordinates.

adjust H and V. Tap add geodetic coordinates to all the local point records.

WR 3ODQH

projection.

to update the local coordinates based on the latest

and tap

3ODQH WR *HRGHWLF

&KHFN

screen, select all points, and to

screen, select all points, tap

to verify the accuracy of the

and

5HFDOFXODWH

. This will

*HRGHWLF

Managing GPS Coordinates with TDS

Survey Pro for Windows CE uses a binary file with the extension *.job. A .JOB file point record will contain a point name, plane location (N, E, Z), and a description. It may also contain geodetic coordinates for points calculated, imported, or measured with GPS, as well as poly lines, alignments, layers, attributes, and automatic line work structures.

This section describes different ways to manipulate geodetic coordinates with both Survey Pro and Survey Link. Survey Pro Manual Mode and Edit Points describe how to edit and utilize geodetic coordinates for projection cal culations. Import GPS Coordinates describes how to merge a *.CR5 file and the *.GPS file generated with a DOS localization. Survey Link Import and Export describe how to use Survey Link to convert sets of plane and geodetic coordinates to and from ASCII and/or .CR5 files.

Survey Pro

Manual Mode

You can use without the need to connect to a receiver.

1. Go to Settings receiver

You can do the following procedures with manual entry:

• Base Setup: You can set the base on any existing point from the job file. You can also set the base on a new point and enter the autonomous position by hand. In

GPS Base Station screen contains a to void the current base setup.

Manual Entry

from the Job menu and select

and

Brand

mode to perform all projection calculat ions

for

Manual Entry

for receiver

Manual Entry

&OHDU

button. Use this button

Manual Mode

Model

mode, the Current

Managing GPS Coordinates

• GPS Control Point: You can ‘occupy’ a localization and hand enter a geodetic location.

• GPS Check Point: You can ‘occupy’ a checkpoint and hand-enter a geodetic location. The local coordinate of your entered geodetic location is compared to the selected point and displayed on the Results

tab.

&RQWURO 3RLQW

Edit Points

You can edit all of a point’s values using the Edit Points screen from the Job reference manual. Below are some special instructions for editing geodetic coordinates.

menu. This is described in more detail in the users and

1. Select the point you want to edit and tap point in the list to open the edit screens.

2. The three cards of the Edit Point properties and the plane and geodetic locations of the sel ected point.

3. On the Geodetic card, you can tap Point Flags screen. This screen allows you to edi t the flags associated with GPS points:

• Set up group: This flag identifies groups of points collected

from an autonomous base setup. For more information on set up groups, see Page 41.

• GPS Control Point H/V: These flags identify points to be

included in the localization control point list and whether to use those points for the hori zontal and/or vertical solution. For more information on set up groups, see Page 41.

4. If you change either the plane or geodet ic location, and the point has geodetic coordinates, will be warned of the possible consequences, and, depending on your projection settings, prompted to rectify the plane and geodetic coordinate before accepting.

screen display the current

$GYDQFHG

(GLW

, or double tap the

to open the Edit GPS

GPS User’s Manual

Import a .GPS File

You can use control point measurements (in a *.GPS file) with the local plane coordinates in a job file.

1. Open the job with the project ’s plane coordinates. You can open the *.CR5 file directly and it will be converted into a .job file or you can open a new .job file and import the C R5 coordinates.

2. Go to Import Coordinates select, coordinates.

3. Specify the units of the *.GPS file (for the heights) and tap OK.

4. The GPS coordinates and control point flags for each point in the *.GPS file will be merged with the plane coordinates for the corresponding points.

5. If you have more than one *.GPS file associated with a set of coordinates, you can import them one at a time. The coordinates from each .GPS file will be assigned a unique set up group so you can use them for different localization solutions.

Note: If duplicate points are found, you will be prompted to overwrite or rename. If you choose to rename, a new point is created with the original plane coordinate and the new geodetic coordinat e.

Import Coordinates

(*.GPS)

and pick the *.GPS file associated with the plane

from the Job menu to merge DOS

from the Job menu. For file

Type

Managing GPS Coordinates

Survey Link

File Import

To create a .CR5 or an ASCII text file from a .JOB file, go to Survey Pro CE Import/Export from the Transfer menu.

1. Enter the

2. Specify the

3. Specify what part of the point record you wish to import: the plane (

4. Specify if you want to create a .CR5 or an ASCII text file.

5. Enter the

6. Press

Job file name

Distance units

) coordinates or the GPS (

NEZ

File name

,PSRUW

of the job to import.

of the coordinates to generate.

Lat, Long, Ht

of the file to be created.

) coordinates.

GPS User’s Manual

File Export

To create a .JOB file from either an ASCII text file or a .CR5 file, go to Survey Pro CE Import/Export

from the Transfer menu.

1. Specify the

2. Specify the point record type of the input file. Choose ( ) to create GPS point records. Choose (

standard point records.

If you export a job file with GPS point records, records will be created with the geodetic coordinates from your input file and a default plane coordinate of (0.0, 0.0, 0.0). You can then use the Readjust Points function to generate mapping plane coordina tes for the exported geodetic coordinates.

If you export a job file with plane point records, records will be created with the plane coordinate only.

3. Specify the file format, .CR5 or ASCII, of the input file.

4. Enter the

5. Press

Distance units

File name

([SRUW

of the coordinates to export.

N, E, Z

of the file to be created.

Lat, Long,

) to create

Post Processing Data Collection

Post processing data collection uses GPS raw data stored in the receiver’s internal memory. Raw data from multiple receivers is combined and then PC software is used to process the base line measurements. The following secti on describes how to start recording raw data in the receiver internal memory for both post processing only data collection and simultaneous RTK and post processing data collection.

Field Procedure

Turn On Post Processing

1. Go to Settings from the Job menu.

2. On the Post Process interval.

Note: For simultaneous RTK and post processing data collection, this is all you need to do. Receiver recording will be started automatically when you configure the R TK base and rover. Data collection sessions will be completed automatically when you occupy an RTK point. If you wish to do post processing only data collection, you need to complete the next step before tapping OK.

3. On the Receiver card, select the correct want to use simultaneous RTK plus post processing data collection, select only data collection, either static or stop and go, set the

Mode

4. Tap 2..

Post Process

card, specify a non-zero recording

GPS Mode

mode. If you want to do post processing

RTK

. If you

GPS

GPS User’s Manual

Start Recording in Receiver

1. With the

2. Choose Start Static Rx record raw data at a stationary setup. Choose Start Stop/Go Rx. if you want to configure a receiver to do stop and go dat a collection.

3. Tap values.

4. Tap vertical measurement.

5. Tap and begin logging GPS raw data.

6. Tap data.

Note: receiver’s internal memory. It does not send the station or antenna information. For a static receiver, you will automatically be taken to the Receiver Session screen to enter your station site ID and send the antenna information. For a stop and go receiver, you will be prompted to start your first occupation using the Receiver Session screen.

GPS Mode

&KDQJH 6HWWLQJV

6HWXS +5

6WDUW 5HFRUGLQJ

6WRS 5HFRUGLQJ

6WDUW 5HFRUGLQJ

set to

to select an antenna type and enter the slant or

to create a new file in the receiver memory

to close the file and stop logging GPS raw

only begins the logging of raw data to the

Post Process

. if you want to configure a receiver to

to select a new

, go to the Survey menu.

Rec Interval

Threshold

Data Collection

1. With the screen from the Survey

2. Choose if you wish to

Receiver file only job file,

Survey Pro job and you will be prompted to put the point on the autonomous layer. If you choose to store the point in the

GPS Mode

then the site ID must be a unique point name in the

set to

. If you choose to store the point in

Post Process

menu.

Store point in: Receiver and job file

, go to the Data Collection

Receiver and

or the

Receiver

file only,

you are not prompted for layer or attributes.

the site ID can be any valid name for the receiver and

Post Processing

Note: If you are using this screen with

can store points only on the receiver’s file. To store points in the receiver and in Survey Pro, use a regular RTK data collection routine and set the raw data for

3. Enter a

Note: If the Site ID or description is not valid for your model of receiver, you will be prompted to modify them.

4. Enter a

Log Until Stop

Note: In order for a timed session to stop properly, you cannot tap

&ORVH

out of this screen until the timed session is finished. If you

wish to exit this screen while the session is underway, you should use

Log Until Stop

5. Tap

6WDUW

receiver raw data. If you are storing the point in Survey Pro, you will be prompted for the autonomous layer and attributes (if set) at this point.

and

Site ID

Duration

to mark the beginning of this site occupation in the

for this session. If you enter 0 or if you check

, the session will continue until you tap

+ Rx.

Description

GPS Mode

for this point.

set to

RTK

6WRS

, you

6. If you specified a

Elapse

choose to record until stop, t h e When the session is done, Survey Pro will send an end of occupation event marker to the receiver.

7. You can end a session by tapping

count down or up depending on your receiver. If you

Duration

, you can watch the time

Remain

6WRS

Elapse

field shows

Remain

”…”

GPS User’s Manual

Office Procedure

1. Use the software supplied by the receiver manufacturer to download the files from receiver internal memory onto your PC.

2. Use your GPS baseline processing software to combin e the raw data from different receivers and generate GPS base lines.

Note: See the documentation supplied with your PC software for details on downloading and processing GPS raw data from the receiver’s internal memory.

Tutorial Jobs

This section contains sample jobs to illustrate all of the main functions of Survey Pro GPS Module. Each job illustrates different horizontal and vertical projection methods as well as different GPS field procedures.

Before Starting

• Make sure you have the file demofile.txt in the same directory as the Survey Pro executable (usually in Disk\Program Files\Survey Pro).

• Make sure you have the files TDSControl_Ground.job and TDSControl_ORNorth.job loaded on the machine (usually in Disk\SurveyPro Jobs)

• Make sure you have the geoid files Oregon G99.ggf and North America EGM96.ggf in the \Disk\Geodata directory.

• Make sure the Standard and GPS modules are registered.

• Make sure you are in GPS Mode. If the instrument/receiver icon

on the title bar shows a total station, tap the icon and switch to GPS Mode.

• Make sure the and the

Model

on the Receiver

Brand

is set to

Demo Mode

card is set to

Manual Mode

Existing Job: Ground – TDS Localization

Objectives

This tutorial job will teach you:

•

How to generate local coordinates in an existing ground lev el coordinate system using new GPS measurements.

•

How to set the RTK base and rover.

•

How to occupy contro l points and solve a TDS Localization adjustment.

•

How to move the base station receiver to both measured and existing plane points.

GPS User’s Manual

Scenario

Your firm has done many jobs over the years at a particular site. You want to use your RTK system to generate new coordinates in this existing coordinate system. The original coordinate system was based on an assumed bearing, so you have no idea how the coordinate grid is oriented with respect to geodetic north.

Procedure

1. Open the existing job file: TDSControl_Ground.job.

• Make sure you are in GPS mode and then check the settings.

2. Select a geoid model to use with the job.

• From the GPS Survey menu, tap Vertical card.

• Tap

3. Set the RTK base station on a new project point and GET an autonomous position.

• From the GPS Survey menu, tap

• Tap

• Enter an antenna height and tap

• Tap

• Since this job has coordinates already, we need to collect

• Tap

4. Setup the Rover

6HOHFW *HRLG

and Oregon G99.ggf as the geoid fi le to use.

Current GPS Base screen.

6HWXS

and type in

*(7

to get autonomous position from receiver. Tap SET

to configure the base receiver.

control points to solve the Localization adjustment. At the prompt to solve projection, tap Current GPS Base information screen.

&ORVH

to return to main menu.

and select Geoid99 (Conus) as the model,

newBase

3URMHFWLRQ

%DVH 6HWXS

in the

&RQWURO 3RLQWV

Base Point

1H[W !

and select the

to open the

control.

to return to the

• From the GPS Survey menu, tap Rover Setup

Rover Setup

screen.

to open the

Trouble Shooting

• Enter the antenna measurement for the rover.

• Tap

5. Collect control points.

• From the GPS Survey menu, tap Control Points.

• Collect control points

• On the Occupy Control Point

6. Solve Localization.

• Tap

• The control points you just collected are listed in the

• Tap

6HW 5RYHU

names in the list) and tap

both

Horizontal

the control point geodetic coordinate to the selected point record.

3URMHFWLRQ

6ROYH /RFDOL]DWLRQ

control. Make sure they are all selected for horizontal

Points

(H) and vertical (V) control.

6ROYH!

the residual/misclosure values for each point. In this case, the residuals are all 0.0, since the meas urements were simulated and mathematically perfect.

CHAP, 54

control (or selecting them from the map or

Point

&RQWURO

to calculate the Localization solution and display

and

Vertical

to open the Projection

, and 1 by entering their

screen, flag each point to use as

control points. Tap

information screen. Tap

$FFHSW

to add

Control

• Tap

1H[W!

to examine the solution parameters.

• The scale is 0.999998631. This is approximately –1.4ppm, or less than 2mm in 1Km, and would be considered near perfect. Solutions using actual field measurements will usually have a scale around 15-25 ppm.

• The rotation is 1-57-48. You may or may not be able to evaluate this answer. In our example, the job file ground coordinates were created by scaling and translating Oregon North map projection coordinates, so the rotation is the negative of the meridian convergence on OR North. In other jobs, the bearings may have arbitrary orientation, in which case the rotation value will adjust to the local bearings.

GPS User’s Manual

• The Delta values represent the shift from the TDS Localization stereographic zone false northing and easting (100000.0, 100000.0) to the local system (5000.0, 5000.0).

• Tap

• You are prompted to store this Localization sit e in the

• Upon exiting the Solve Localization

7. Check points.

• Select Point 3 and tap

• Tap

8. Data Collection

• From the Survey Menu, tap

$FFHSW

to apply the solution. You are prompted that this

will update the plane coordinate of all GPS points. Tap 2. to apply the localization solution to all GPS measured points. Your new autonomous base point’s local coordinates will also be calculated.

database. Give the site a name and tap 2..

wizard, tap Projection information screen to return to the Control Points screen.

&KHFN

. Results should be perfect. In the field you would expect check points to be within the measurement precision of your GPS s ystem.

$FFHSW

and review the results on the Results

&ORVH

to return to main menu.

'DWD &ROOHFWLRQ

and collect some GPS measurements. You can tap measure one point at a time. You can tap an offset from a reference point. You can tap

collect many points either automatically by an interval, or manually.

. Start at point 301

2IIVHW

&ORVH

on the

tab.

3RLQW

to measure

)HDWXUH

9. Move the base to a point in the coordinate file measured with GPS.

• From the Survey Menu, go to

point 1 and tap

• Measured coordinates for Point 1 are recalled and ready to

6(7

1H[W!

%DVH 6HWXS

, tap

6HWXS

, select

• Tap

10. Check points and add control point.

6(7

to configure the base station. Since the Localization adjustment is already solved, you will not be prompted to solve the projection again.

Trouble Shooting

• Go to Control Points Since you have not yet set the rover, tap prompt, then retap

perfect.

• Add Control Point 2. Deselect the H/V check when you are collecting it. This point will be used only if necessary.

11. Move the base to a point in the coordinate file not measured with GPS.

• Go to Base Setup

point does not have geodetic coordinates, you are prompted to compute coordinates from the known (N,E,Elev) and the

latest projection solution. Tap 2.

Note: This action is equivalent to the TDS “Move Base” routine in the DOS software.

• The geodetic coordinates for point 4 are computed. Tap

to configure the receiver.

12. Set the Rover.

13. Check points.

. Select point 2 and tap

&KHFN 3RLQW

, select point 4 and tap

. The results should be

&KHFN 3RLQW

6HW 5RYHU 1RZ

1H[W!

. Since this

at the

6(7

• Go to Control Points

The results should be perfect.

. Select point 2 and tap Check Point.

GPS User’s Manual

Reuse Localization Solutions

Objectives

This tutorial job will teach you:

•

How to reuse a localizatio n solution in a new job.

•

How to select a Localization adjustment record from the coordinate system database.

•

How to use a control file.

Scenario You want to return to the project site from the first tutorial to add

some new measurements. You want to us e a new job file for this new work, but you do not want to collect the control measurements again.

Procedure

1. Create a new job.

• Choose already exists in the control file, since we can not load the control file if there are common point names in both jobs.

• Go to the Files

TDSControl_Ground.job

2. Set the projection.

• From the Survey Menu, tap card, tap

• Tap

• In the

• Tap 2.. The Localization solution is now set.

3. Set up base and rover.

• Put the base st ation on point CHAP (or any other GPS

3LFN IURP 'DWDEDVH

selection screen.

pick the name you gave to the Localization site in the first tutorial.

measured points from the control file) and SET the base.

as the first point. Do not choose a point that

1001

card from the Job, Settings screen. And select

as the control file

3URMHFWLRQ 6HWXS

Data Base

box, select

3URMHFWLRQ

to open the Localization Data Base

View Sites

. On the Horizontal

. From the

Site

control,

• Go to Rover Setup

4. Check point

Trouble Shooting

. Set the rover

• Go to Control Points results should be near perfect.

5. Feature Collection

• From the Survey Menu, tap

• Tap

• Allow this to run for a minute to collect a number of points.

Note: Notice points from continuous collection are connected with a line on the Map tab.

)HDWXUH

interval ( line work (Ctrl. L) and add t h e description for this feature to the line work. This will draw a line in real time as points with this description are collected.

6WDUW

to start the continuous dat a collection.

Tap View Points t o see how many points you have stored s o far. Tap

, choose

min). Before tapping

0.1

to open the Occupy Data Points

'RQH

and select point 3 for a

'DWD &ROOHFWLRQ

Continuous by Time

6WDUW

when you are finished.

&KHFN

. The

and enter a small , hot key to the auto

screen. Tap

$FFHSW

One Point Localization

Objectives

This tutorial job will teach you:

•

How to start a new job with one point and begin measuring ground level distances without any existing control.

Scenario You show up at a new job site where no previous coordinates exist.

You want to use RTK to create a new ground level coordinate system for a legal and topo survey.

GPS User’s Manual

Procedure

1. Create a new job.

• Enter 1 as the default starting point name and accept the default start location (5000, 5000, 100).

• Creating this job will unload the control file (since it also has a point 1). This is what we want for our new job.

2. Set the base on your one point.

• Go to Base Setup

• Choose

receiver.

• Tap

3. Solve a One Point Localization.

• With your base point as the one control point, tap Solve> and Accept. At the prompt, enter a name for this Localization site in the coordinate system database.

4. Set the rover.

5. Data collect points 2,3,4,

6. Move base to point CHAP.

7. Collect Check Point on 2, results should be perfect.

*(7

6(7

. At the projection prompt, tap

and pick point 1.

to receive an autonomous position from the

CHAP

6ROYH 1RZ

Trouble Shooting

Mapping Plane with GPS and Conventional Measurements

Objectives

This tutorial job will teach you:

•

How to use GPS Stake Out.

•

How to calculate combined scale factor for conventional measurements.

•

How to coordinate conventional measurements on the mapping plane.

•

How to use COGO functions with the combined scale factor.

Scenario You need to lay out petroleum well site at coordinates specified in a

US State Plane map projection zone. Some total station measurements will be used to add points to the project.

Procedure

1. Open TDSControl_ORNorth.job.

2. Save this job as TdsControl_OrNorth COPY.job so the original file is available for the next tutorial.

• Go to the Job

make sure Post Process

3. Check the horizontal and vertical projection.

• Go to Projection

card notice the of the zone record selected for this job file. Tap

6KRZ 'HWDLOV

map projection zone.

• On the Vertical

name used.

• To select a different map projection, tap

Mapping Plane Setup screen, you can select either a map projection zone or a calibrated site as the new projection

, Settings screen. On the Measure Mode card,

Store GPS Raw Data

card make sure recording interval is turned on.

from the Survey menu. On the Horizontal

to review the numeric parameters for this

card notice the geoid model record and file

is set to

+ Rx. Raw.

6HOHFW =RQH

On the

. On the

GPS User’s Manual

record. You can also key in a custom map projection zone using the

.H\ ,Q 3DUDPHWHUV

wizard.

• Make sure Oregon North is still selected and tap are prompted that the conventional survey scale factor is set to 1.0, which is probably not the correct value for this map projection. You can tap calculator to set the conventional scale factor now. We will set our scale factor when we start conventional measurements, so tap

4. Set up the base station.

• Go to Base Setup coordinate is computed from the plane coordinate using the reverse transformation and the selected geoid model.

5. Set the rover

6. Data collection.

• Go to Data Collection

. These are the corners of a ‘virtual’ quarter section.

OIP4

• Data collect Point stake out. Over write the existing coordinate for 101 in the file.

7. Stake Out

• Go to Stake Points and select Point

and select point

8SGDWH 6FDOH

/DWHU

to finish setting the projection.

and collect points

. This will be used as the well center to

101

to use the scale

MANE

101

)LQLVK

. You

. The geodetic

OIP1, OIP2, OIP3,

8. Tap

9. Navigate to the point.

Note: In the field, you would navigate to the point, place your mark and then occupy the staked position. In order to get the demo to recognize that you want to stake point 101, you must first switch to

2&&83<,1*

6ROYH!

• Change from prompt.

and then

6WDNH!

529,1*

to open the GPS Staking

2&&83<,1*

. Enter Point

screen.

201

Trouble Shooting

• Stake out to Point location move to the rover location, as you get closer.

has now begun. Watch the design

101

• Press

10. Conventional measurements

• Tap the instrument icon in the title bar and switch to

• Go to the Surveying

11. Set up back sight.

• Go to Back Sight Setup

• You are prompted that the sc ale factor for this point is

• Use the Scale Calculator

12. Side shots and traverse.

'21(

to accept this staked location and return to the

Stake Points screen.

Conventional Mode

Select

Setups

measurements because your coordinate system is a mapping plane. ( If you were using localization, you will generally leave

scale factor for conventional mea surements at 1.0.) Tap

and tap

different from the current scale factor. Tap

setup. A new mode record is written to raw data.

Use Scale Factor

. You need to apply a scale fa ctor to your conventional

6FDOH

to open the Scale Calculator

6ROYH

card from the Job, Settings screen.

and

Prompt to Reset Scale With New

wizard.

. Occupy

to solve the scale fact or for this

, and back sight

OIP1

&KDQJH 6FDOH

&DOF

OIP2

• Take a 100.0-m the horizontal distances are scaled.

• Take a At the prompt, tap

• You will be prompted to reset scale since your elevation has changed significantly.

• The scale is updated and a new mode record is written to the raw data. Subsequent shots are scaled with the new value.

13. Using the scale factor in COGO calculations

• Go to Point in Direction

7UDYHUVH

6LGH 6KRW

shot at AR

. View the results tab to see how

7UDYHUVH 1RZ

from the Cogo menu.

= 0.0, ZE = 45.0000, SD = 1000.0

GPS User’s Manual

• Select a starting point and a direction.

• Enter a horizontal distance in the Horz Dist field, tap the

corresponding power button, and choose Apply Scale Factor to scale the input distance. Notice how the entered horizontal distance has now been scaled to your mapping plane grid.

Trouble Shooting

Hardware Configuration

You attempt to auto detect and the program fails to find the baud rate of the receiver.

Check to make sure you selected the correct brand and

model. The port you are connected to may be ‘broken’ or

temporarily unavailable. Plug into another port and try again.

If you cannot detect the baud from any of the ports, toggle

the power on the receiver and try again. If you still cannot connect, do a soft reset of your receiver

hardware. If you still cannot connect, do a hard reset of your receiver

hardware.

You attempt to auto detect baud rate and port and it takes several seconds to check each baud rate.

You are plugged into a port that is sending out other

traffic, this receiver is probably in base mode and is sending RTK corrections out the port you are connected to.

Plug into a different port and t ry again.

You attempt to change or check the ra dio channel and the radio does not go into command mode after you toggle the power

Older versions of the radio firmware do not behave well at

faster bauds. Set the data collector to receiver baud rate to 9600 and try again.

If this still does not work, try leaving the radio unplugged

for five seconds before plugging it back in.

GPS User’s Manual

You attempt to change the radio channel on a radio that supports software breaks and you are still prompted to toggle the power on and off.

The radio baud rate is not set at the correct value for this

radio. Make sure the radio baud rate is set correctly and try again.

Base Setup

You attempt to get an autonomous position from the base receiver and you get the message: "

again.

Check to make sure the antenna is connected.

Check the Sky View

make sure you are tracking satellites.

You attempt to get or set the base or rover and you get the message: “

receiver. Check receiver settings and communication and try again.

Survey Pro could not execute that command in the

Check to see if you are communicati ng with the receiver. Check the GPS Status getting the

The receiver may be busy doing other things. If you attempt to set the receiver when it is still doing a cold start, it will not respond to all commands.

No COM

Not enough satellites for solution. Try

card on the GPS Status screen to

screen and make sure you are not

message on any of the cards.

”

Radio Communication

You set up the base and the Tx. Light on the base radio is not blinking at a regular rate.

Make sure the radio serial cable is connected.

Make sure the radio antenna is connected.

Make sure the base radio COM port and baud rate is

correct.

Trouble Shooting

You set up the rover and the Rx. Light on the rover radio is not blinking.

Make sure the radio serial cable is connected.

Make sure the radio antenna is connected.

Make sure the rover radio COM port and baud rate is

correct. Make sure the base and rover radios are on the same

channel.

You set up the rover and the Rx. light is blinking sporadically.

The radio is receiving interfering signals on this channel.

Switch the base and rover radios to a different channel.

You set up the rover and the Rx. light is blinking but the Data Link card on the GPS Status screen says

Make sure the radio serial cable is connected.

Make sure the rover radio COM port and baud rate is

correct.

No Data from Radio

Projection Solutions

You set up a mapping plane requiring data files for datum conversion or you are using geoid modeling and you get a message about files not found.

Make sure the required data files are in the directory

specified on the card of the Job

You select a custom projection file and you get a message about file format not valid.

The .CS5 or .PJ5 cus tom projection file has been

corrupted. Open the file in the text editor and repair it or generate a new file using Survey Link.

You solve localization and the horizontal or vertical residuals are larger than the measurement precision of the instrument, or

Path to Data Files

, Settings screen.

field on the Projection

GPS User’s Manual

when you do a check point, the errors are larger than the instrument precision.

Make sure you did not occupy the wrong control point.

Check the Map visually inspect the location of control points.

The measurements to one or more control points are of

poor precision. Check the control point records in the .RAW file and verify the RH and RV values.

Taking measurements

The rover receiver status reports

Communication with the receiver is OK, but the receiver

is not returning a complete response to the status or position message. Check antenna cable and try again.

The rover receiver status reports used even when more than 4 satellites are being tracked.

Some receivers will not calculate position when there are

no RTK corrections received over the radio link. Check the Data Link any radio problems.

tab on the Control Points screen to

No Data

No RTK solution

card on the GPS Status screen and remedy

and 0 satellites

Post Processing

You attempt to start recording in a receiver and you get the message “

receiver. There is a problem with the receiver internal memory.

Survey Pro could not execute that command in the

The internal memory card is full or missing. Check the

internal memory card and try again.

References

Books:

The following books are available from various sources, including the America Congress on Surveying and Mapping:

5410 Grosvenor Lane, Bethesda MD, 20814 Phone: (301) 493 0200 Email: books@acsm.net

For a basic description of GPS hardware, field procedures, network design, planning observations:

Van Sickle, Jan. GPS for Land Surveyors 300pp. ISBN 1-57504-041-7

For a more detailed reference on GPS datums and coordinate systems, signals, psuedo-range observables, and mathematical models:

Hofmann-Wellenhof et al. GPS Theory and Practice, 3 1994, Springer-Verlag Wein (Austria). 355pp. ISBN 3-21182591-6

1996, Ann Arbor.

Eddition

For an advanced discussion of GPS carrier signals, adjustment of GPS observation networks, and coordinate transformations:

Leick, Alfred. GPS Satellite Surveying, 2 Wiley & Sons Inc. 584pp. ISBN 0-471-30626-6

GPS Information on the Internet: For current links on GPS constellation status, GPS and map

projection references, and other geodetic information sources, go to the TDS web site at www.tdsway.com Pro for Windows CE | GPS Links.

and click on Support | Survey

Edition 1995, John

SURVEY PRO

for Windows® CE

GPS Reference Manual

2002 Tripod Data Systems, Inc.



GENERAL. This License shall be governed by and construed in accordance with the laws of the State of Oregon, United States of America.

The warranties and remedies set forth above are exclusive and in lieu of all others, oral or written, express or implied. Statements or representations which add to, extend or modify these warranties are unauthorized by LICENSOR and should not be relied upon by you.

Some states do not allow the exclusion or limitation of implied warranties or liability for incidental or consequential damages, so the above limitations or exclusions may not apply to you.

Survey Pro is a registered trademark of Tripod Data Systems, Inc. Windows CE is a registered trademark of Microsoft Corporation.

TRIPOD DATA SYSTEMS SOFTWARE LICENSE AGREEMENT

LIMITED WARRANTIES AND LIMITATION OF LIABILITY

U.S. GOVERNMENT RESTRICTED RIGHTS

TRADEMARKS

.MAN-CESURVPROGPS 10152002

Table of Contents

Job Menu............................................................................................R-5

Settings ...................................................................................R-6

Receiver Settings....................................................................................R-7

Measure Mode Settings ........................................................................R-8

Projection Settings...............................................................................R-10

Post Process Settings...........................................................................R-11

Receiver Settings..................................................................................R-12

Survey Menu – RTK.......................................................................R-19

GPS Status............................................................................R-20

Base Setup ............................................................................R-23

Base Receiver Antenna........................................................................R-27

Rover Setup..........................................................................R-28

Rover Receiver Antenna .....................................................................R-29

Control Points......................................................................R-29

Data Collection....................................................................R-33

Projection Screen.................................................................R-37

Horizontal Card...................................................................................R-37

Vertical Card ........................................................................................R-56

Receiver Information.......................................................... R-60

Readjust Points....................................................................R-61

Projection Calculator ..........................................................R-63

Survey Menu – Post Processing...................................................R-67

GPS Status............................................................................R-68

Start Static Rx.......................................................................R-69

Start Stop/Go Rx.................................................................R-70

Data Collection....................................................................R-71

Receiver Information.......................................................... R-72

Stakeout Menu................................................................................R-73

Stake Points..........................................................................R-74

Stake to Line.........................................................................R-76

Slope Staking .......................................................................R-79

Slope Staking – Screen Four...............................................................R-79

Line and Offset....................................................................R-82

iii

Curve and Offset.................................................................R-82

Spiral and Offset..................................................................R-82

Show Station and Offset.....................................................R-84

Show Station – Screen Two................................................................R-84

Store Offset Points...............................................................R-85

Stake DTM............................................................................R-86

DTM GPS Shot.....................................................................................R-86

Where is Next Point............................................................R-88

Inverse Menu...................................................................................R-89

Cogo Menu.......................................................................................R-89

Curve Menu .....................................................................................R-89

Adjust Menu....................................................................................R-89

Transfer Menu.................................................................................R-89

Job Menu

A: Settings

B: New C: Open D: Edit Points E: Edit Polylines F: Edit Alignments G: Auto Linework H: Save As I: Import Coordinates J: Export Coordinates K: Job Information L: View Raw Data M: Backup Job N: Collection Mode O: Register Modules P: About S urvey Pro Q: Exit

Items in gray are covered in the standard Reference Manual.

Spectra Precision Survey Pro CE v3.60 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual