Trimble 8311891 Users Manual

1

GETTING STARTED GUIDE

Trimble SPS855 GNSS Receiver

Version 4.60
Revision A
June 2012

1

Corporate Office

Trimble NavigationLimited
935 StewartDrive
Sunnyvale, CA 94085
USA

www.trimble.com

Heavy Highway business area

Trimble NavigationLimited
Heavy Highway business area
5475 Kellenburger Road
Dayton, Ohio 45424-1099
USA
800-538-7800 (tollfree in USA)
[phone] Phone
[phone] Fax

www.trimble.com

Email: [e-mail] m

Legal Notices

© 2006–2012, Trimble Navigation Limited. All rights reserved.
Trimble, and the Globe & Triangle logo are trademarks of Trimble
Navigation Limited, registered in the United States and in other
countries. AutoBase, CMR, CMR+, Connected Community, EVEREST,
HYDROpro, Maxwell, Micro-Centered, Trimble Geomatics Office,
SiteNet, TRIMMARK, TRIMTALK, TSCe, VRS, Zephyr, and Zephyr
Geodetic are trademarks of Trimble Navigation Limited.
Microsoft, Windows, and Windows Vista are eitherregistered
trademarks ortrademarks of MicrosoftCorporationin the United States
and/orother countries.
The Bluetooth wordmark andlogos are owned by the Bluetooth S IG,
Inc. and any use of suchmarks by Trimble Navigation Limitedis under
license.
All other trademarks are the property oftheirrespective owners.
Support for Galileo is developed under a license of the European Union
and the European Space Agency (SPS985/SPS855/SPS555H).

NTP Software Copyright

© David L. Mills 1992-2009. Permissionto use, copy, modify, and
distribute this software andits documentationfor any purpose with or
without fee is herebygranted,provided that the above copyright notice
appears in allcopies and that boththe copyright notice and this
permissionnotice appear in supporting documentation,and that the
name University of Delaware not be used in advertising or publicity
pertaining to distribution of the software without specific,written prior
permission. The University of Delaware mak es norepresentations about
the suitability this software for any purpose. It is provided "as is" without
express orimplied warranty.

Release Notice

This is the April 2012 release (Revision A) of the SPS M odular Receiver
documentation. It applies to v ersion 4. 60 of the receiver firmware.

Product Li mited Warranty Information

For applicable product LimitedWarranty information,please refer to the
Limited Warranty Card includedwith this Trimble product,orconsult your
localTrimble authorized dealer.

COCOM limits

This notice applies to the SPS351, SPS555H, S PSx61, SPS855, and
SPS985 receivers.
The U.S . Department of Commerce requires that all exportable GPS
products containperformance limitations so that they cannot be used in
a mannerthat could threatenthe security of the United States. The
following limitations are implemented on this product:
– I mmediate access tosatellite measurements and navigationresults is
disabledwhen the receiver velocity is computed to be greaterthan
1,000 knots, or its altitude is computed to be above 18,000 meters. The
receiver GPS subsystem resets until the COCOM situation clears. As a
result, all logging and stream configurations stop until the GPS
subsystem is cleared.

Notices

Class B Statement – Notice to Users. This equipmenthas been

tested and found to comply with the limits for a Class B digital device
pursuant to Part 15 of the FCC Rules. Some equipmentconfigurations
include an optional 410 MHz to470 MHz UHF radio transceiver module

compliant with Part 90. These limits are designed to provide reasonable
protection againstharmful interference in a residential installation. This
equipment generates, uses, and can radiate radiofrequency energy and,
if not installedand used in accordance withthe instructions,may cause
harmfulinterference to radio communication. However, there is no
guarantee that interference willnotoccur in a particularinstallation. If
this equipment does cause harmfulinterference to radio or television
reception, which can be determinedby turning the equipmentoff and
on,the user is encouraged totry to correct the interference by one or
more of the following measures:
– I ncrease the separation between the equipmentand the receiver.
– Connect the equipment into an outlet on a circuitdifferent from that to
which the receiver is connected.
– Consult the dealer or an experienced radio/TV technician for help.
Changes and modifications not expressly approved by the manufacturer
or registrant of this equipmentcan void y our authority to operate this
equipment under Federal Communications Commissionrules.
This equipmentmust be installed and operated in accordance with
provided instructions and the antenna(s) used forthis transmitter must
be installed to provide a separation distance of at least 20 cm from all
persons and must not be co-locatedoroperated in conjunction with any
otherantenna or transmitters (except in accordance with the FCC multi­transmitterproduct procedures).

Canada

This Class Bdigital apparatus complies withCanadianICES-003.
Cet appareilnumérique de la classe B est conforme à la norme NMB-003
du Canada.
This apparatus complies withCanadian RSS-GEN, RSS-310, RSS-210,and
RSS-119.
Cet appareilest conforme à la norme CNR-GEN, CNR-310, CNR-210, et
CNR-119 du Canada.

Europe

The product covered by this guide are intended to be
used in all EU member countries, Norway, and
Switzerland. Products been tested and found to comply
withthe requirements for a Class B device pursuant to
European CouncilDirective 89/336/EEC onEMC, thereby satisfying the
requirements for CE Marking and sale withinthe European Economic
Area (EEA). Contains a Bluetooth radio module. These requirements are
designed to provide reasonable protection against harmfulinterference
when the equipmentis operatedin a residential or commercial
environment. The 450 MHZ (PMR) bands and 2.4 GHz are non­harmonized throughoutEurope.

CE Declaration of Conformity

Hereby, Trimble Navigation,declares that the GPS receivers are in
compliance with the essential requirements and other relevant
provisions of Directive 1999/5/EC.

Australia and New Zealand

This product conforms with the regulatory requirements of
the AustralianCommunications and Media Authority
(ACMA) EMC framework, thus satisfying the
requirements for C-Tick Marking and sale withinAustralia
and New Zealand.

Restriction of Use of Certain Hazardous Substances in Electrical

and Electronic Equipment (RoHS)

Trimble products in this guide comply in allmaterial respects with
DIRECTIVE 2002/95/EC OF THE EUROPEAN PARLIAM ENT AND OF THE
COUNCIL of 27 January 2003 on the restriction of the use of certain
hazardous substances in electrical and electronicequipment (RoHS
Directive) and Amendment2005/618/EC filedunder C(2005) 3143, with
exemptions for lead in solder pursuantto Paragraph 7 of the Annexto
the RoHS Directive applied.

Waste Electrical and Electronic Equipment (WEEE)

For product recycling instructions and more information,
please go to www.t rimble.com/ev.shtml.
Recycling inEurope: To recycle Trimble WEEE (Waste
Electrical and Electronic Equipment, products that run on
electrical power.), Call [phone], and ask for the
“WEEE Associate”. Or, mail a request for recycling
instructions to:
Trimble Europe BV

SPS855 GNSS Modular Receiver Getting Started Guide 2

c/o MenloWorldwide Logistics
Meerheide 45
5521 DZ Eersel,NL

Unlicensed radios in products

This device complies with part 15 of the FCC Rules.
Operation is subject to the following two conditions:
(1) This device may not cause harmful interference, and
(2) This device must accept any interference received,including
interference that may cause undesired operation.

Licensed radios in products

This device complies with part 15 of the FCC Rules.
Operation is subject to the condition that this device may not cause
harmfulinterference.

SPS855 GNSS Modular Receiver Getting Started Guide 3

Safety Information

Before you use your Trimble product, make sure that you have read and understood all safety
requirements.

WARNING – This alert warns of a potential hazard which, if not avoided, could result in severe injury or even

death.

CAUTION – This alert warns of a potential hazard or unsafe practice that could result in minor injury or property
damage or irretrievable data loss.

Note – An absence of specific alerts does not mean that there are no safety risks involved.

Use and care

This product is designed to withstand the rough treatment and tough environment that typically
occurs in construction applications. However, the receiver is a high-precision electronic instrument
and should be treated with reasonable care.

CAUTION – Operating or storing the receiver outside the specified temperature range can damage it.

Regulations and safety

Some receiver models with base station capability contain an internal radio-modem for
transmission or can transmit through an external data communications radio. Regulations
regarding the use of the 410 MHz to 470 MHz radio-modems vary greatly from country to country.
In some countries, the unit can be used without obtaining an end-user license. Other countries
require end-user licensing. For licensing information, consult your local Trimble dealer.

All Trimble receiver models described in this documentation are capable of transmitting data
through Bluetooth wireless technology.

Bluetooth wireless technology, and 900 MHz radio-modems operate in license-free bands.

Note – 900 MHz radios are not used in Europe.

Before operating a Trimble receiver or GSM modem, determine if authorization or a license to
operate the unit is required in your country. It is the responsibility of the end user to obtain an
operator's permit or license for the receiver for the location or country of use.

For FCC regulations, see Notices.

Type approval

Type approval, or acceptance, covers technical parameters of the equipment related to emissions
that can cause interference. Type approval is granted to the manufacturer of the transmission
equipment, independent from the operation or licensing of the units. Some countries have unique
technical requirements for operation in particular radio-modem frequency bands. To comply with
those requirements, Trimble may have modified your equipment to be granted Type approval.

SPS855 GNSS Modular Receiver Getting Started Guide 4

Unauthorized modification of the units voids the Type approval, the warranty, and the operational
license of the equipment.

Exposure to radio frequency radiation

For 450 MHz radio

Safety. Exposure to RF energy is an important safety consideration. The FCC has adopted a safety
standard for human exposure to radio frequency electromagnetic energy emitted by FCC regulated
equipment as a result of its actions in General Docket 79-144 on March 13, 1986.

Proper use of this radio modem results in exposure below government limits. The following
precautions are recommended:

l

DO NOT operate the transmitter when someone is within 20 cm (7.8 inches) of the antenna.

l

DO NOT operate the transmitter unless all RF connectors are secure and any open connectors
are properly terminated.

l

DO NOT operate the equipment near electrical blasting caps or in an explosive atmosphere.

l

All equipment must be properly grounded according to Trimble installation instructions for safe
operation.

l

All equipment should be serviced only by a qualified technician.

For license-free 900 MHz radio

CAUTION – For your own safety, and in terms of the RF exposure requirements of the FCC, always observe these

precautions:
– Always maintain a minimum separation distance of 20 cm (7.8 inches) between yourself and the radiating
antenna.
– Do not co-locate the antenna with any other transmitting device.

Note – 900 MHz radios are not used in Europe.

For Bluetooth radio

The radiated output power of the internal Bluetooth wireless radio is far below the FCC radio
frequency exposure limits. Nevertheless, the wireless radio shall be used in such a manner that the
Trimble receiver is 20 cm or further from the human body. The internal wireless radio operates
within guidelines found in radio frequency safety standards and recommendations, which reflect
the consensus of the scientific community. Trimble therefore believes that the internal wireless
radio is safe for use by consumers. The level of energy emitted is far less than the electromagnetic
energy emitted by wireless devices such as mobile phones. However, the use of wireless radios may
be restricted in some situations or environments, such as on aircraft. If you are unsure of
restrictions, you are encouraged to ask for authorization before turning on the wireless radio.

SPS855 GNSS Modular Receiver Getting Started Guide 5

For GSM/GPRS radio

Safety. Exposure to RF energy is an important safety consideration. The FCC has adopted a safety
standard for human exposure to radio frequency electromagnetic energy emitted by FCC regulated
equipment as a result of its actions in General Docket 79-144 on March 13, 1986.

Proper use of this radio modem results in exposure below government limits. The following
precautions are recommended:

l

DO NOT operate the transmitter when someone is within 28 cm (11 inches) of the antenna.

l

All equipment should be serviced only by a qualified technician.

Installing antennas

CAUTION – For your own safety, and in terms of the RF exposure requirements of the FCC, always observe these

precautions:
– Always maintain a minimum separation distance of 20 cm (7.8 inches) between yourself and the radiating
antenna.
– Do not co-locate the antenna with any other transmitting device.

WARNING – The GNSS antenna and its cabling should be installed in accordance with all national and local

electrical codes, regulations, and practices.
The antenna and cabling should be installed where they will not become energized as a result of falling nearby
power lines, nor be mounted where they are subjected to over-voltage transients, particularly lightning. Such
installations require additional protective means that are detailed in national and local electrical codes.

Trimble receiver internal radios have been designed to operate with the antennas listed below.
Antennas not included in this list are strictly prohibited for use with this device. The required
antenna impedance is 50 ohms.

The antennas that can be used (country dependent) with the:

l

450 MHz radio are 0dBi and 5 dBi whip antennas

To reduce potential radio interference to other users, the antenna type and its gain should be so
chosen so that the equivalent isotropically radiated power (e.i.r.p.) is not more than that permitted
for successful communication.

Battery safety

Internal lithium-ion battery

WARNING – Do not damage the rechargeable Lithium-ion battery. A damaged battery can cause an explosion or

fire, and can result in personal injury and/or property damage.
To prevent injury or damage:
– Do not use or charge the battery if it appears to be damaged. Signs of damage include, but are not limited to,

SPS855 GNSS Modular Receiver Getting Started Guide 6

discoloration, warping, and leaking battery fluid.
– Do not expose the battery to fire, high temperature, or direct sunlight.
– Do not immerse the battery in water.
– Do not use or store the battery inside a vehicle during hot weather.
– Do not drop or puncture the battery.
– Do not open the battery or short-circuit its contacts.

WARNING – Avoid contact with the rechargeable Lithium-ion battery if it appears to be leaking. Battery fluid is

corrosive, and contact with it can result in personal injury and/or property damage.
To prevent injury or damage:
– If the battery leaks, avoid contact with the battery fluid.
– If battery fluid gets into your eyes, immediately rinse your eyes with clean water and seek medical attention.
Do not rub your eyes!
– If battery fluid gets onto your skin or clothing, immediately use clean water to wash off the battery fluid.

WARNING – Charge and use the rechargeable Lithium-ion battery only in strict accordance with the instructions.

To prevent injury or damage:
– Discontinue charging a battery that gives off extreme heat or a burning odor.
– Never attempt to remove, replace, or repair the battery yourself.
– If the battery requires attention, send the receiver to an authorized Trimble Service Center.

Connecting the receiver to a vehicle battery

WARNING – Use caution when connecting battery cable's clip leads to a vehicle battery. Do not allow any metal

object or jewelry to connect (short) the battery's positive (+) terminal to either the negative (-) terminal or the
metal of the vehicle connected to the battery. This could result in high current, arcing, and high temperatures,
exposing the user to possible injury.

WARNING – When connecting an external battery, such as a vehicle battery, to the receiver, be sure to use the

Trimble cable with proper over-current protection intended for this purpose, to avoid a safety hazard to the user
or damage to the product.

Wet locations

WARNING – This product is not intended to be used outdoors or in a wet location when it is powered by the PoE

interface, or by the external power supply. The connection is not waterproof and could be subject to electrical
shorting.

WARNING – The external power adaptor and its associated power cord and plug are not intended to be installed

outdoors, or in a wet location.

SPS855 GNSS Modular Receiver Getting Started Guide 7

Contents

Safety Information 4

Use and care 4
Regulations and safety 4
Type approval 4
Exposure to radio frequency radiation 5
Installing antennas 6
Battery safety 6
Wet locations 7

Introduction 9

Related information 9
Technical support 9

Batteries and power 9

Batteries 9
External power 12

Front panel guide 13

Keypad and display 13
Button operations 14
Power button operations 14
Status screens 15
SPS85x configuration screens 16
SPS85x mode screens 17
SPS85x status screens 18

Configuring system settings 19

Turning off AutoBase technology 20
Signal tracking 21
Variable configuration options 22

Upgrading the receiver 22
Managing application files 23
Default receiver settings 24

Resetting the receiver to factory defaults 25

Default behavior 25

Logging data 25
Adding radio frequencies 26

Adding frequencies for the 450 MHz internal radio using the WinFlash utility 26

Setting UHF reception radio frequencies using the web interface 26
Troubleshooting receiver issues 28

The receiver does not turn on 28

The receiver is not tracking any satellites 28

The receiver does not log data 28

The receiver is not responding 29

The receiver cannot be set up as a base station using the SCS900 software 29
Glossary 30

SPS855 GNSS Modular Receiver Getting Started Guide 8

Introduction

The Trimble SPS855 GNSS Modular receiver is ideal for the following site development and
construction applications:

l

Base station for precision GNSS applications such as site positioning and machine control

l

Location RTK for site vehicle and supervisors

l

Precision RTK rover on-site

l

System integrator applications using Location GNSS augmentation, including OmniSTAR,
Location RTK, SBAS, and DGPS RTCM and Precision RTK

The receiver has a keypad and display, so you can configure the receiver without using a controller
or computer. It can be ordered with a 410 MHz to 470 MHz UHF receive and transmit radio or a
license-free 900 MHz receive and transmit radio.

All the receivers can optionally record GNSS data to the internal memory, and transfer the data over
a serial or Ethernet connection.

Related information

Sources of related information include the following:

l

Release notes – The release notes describe new features of the product, information not
included in the manuals, and any changes to the manuals. They can be downloaded from the
Trimble website at www.trimble.com/support.shtml.

l

Trimble training courses – Consider a training course to help you use your GNSS system to its
fullest potential. For more information, go to the Trimble website at

www.trimble.com/training.html.

Technical support

If you have a problem and cannot find the information you need in the product documentation,
contact your local dealer. Alternatively, go to the Support area of the Trimble website
(www.trimble.com/support.shtml). Select the product you need information on. Product updates,
documentation, and any support issues are available for download.

If you need to contact Trimble technical support, complete the online inquiry form at

www.trimble.com/support_form.asp.

Batteries and power

Batteries

The receiver has one internal rechargeable Lithium-ion battery.

The operational time provided by the internal battery depends on the type of measurement and
operating conditions. Typically, the internal battery provides 10 hours operation as a base station
and 12 hours as a rover during measurement operations using the internal radio.

SPS855 GNSS Modular Receiver Getting Started Guide 9

The receiver can also be powered by an external power source that is connected to the Lemo or
modem port.

All battery operation tests are carried out with new, fully-charged batteries at room temperature
and with full receiver configuration operational. Older batteries, at temperatures significantly higher
or lower than room temperature, will have a reduced performance. Receivers operating with
reduced configuration will have a higher performance.

Battery safety

Charge and use the battery only in strict accordance with the instructions provided.

Internal lithium-ion battery

WARNING – Do not damage the rechargeable Lithium-ion battery. A damaged battery can cause an explosion or

fire, and can result in personal injury and/or property damage.
To prevent injury or damage:
– Do not use or charge the battery if it appears to be damaged. Signs of damage include, but are not limited to,
discoloration, warping, and leaking battery fluid.
– Do not expose the battery to fire, high temperature, or direct sunlight.
– Do not immerse the battery in water.
– Do not use or store the battery inside a vehicle during hot weather.
– Do not drop or puncture the battery.
– Do not open the battery or short-circuit its contacts.

WARNING – Avoid contact with the rechargeable Lithium-ion battery if it appears to be leaking. Battery fluid is

corrosive, and contact with it can result in personal injury and/or property damage.
To prevent injury or damage:
– If the battery leaks, avoid contact with the battery fluid.
– If battery fluid gets into your eyes, immediately rinse your eyes with clean water and seek medical attention.
Do not rub your eyes!
– If battery fluid gets onto your skin or clothing, immediately use clean water to wash off the battery fluid.

Connecting the receiver to a vehicle battery

WARNING – Use caution when connecting battery cable's clip leads to a vehicle battery. Do not allow any metal

object or jewelry to connect (short) the battery's positive (+) terminal to either the negative (-) terminal or the
metal of the vehicle connected to the battery. This could result in high current, arcing, and high temperatures,
exposing the user to possible injury.

WARNING – When connecting an external battery, such as a vehicle battery, to the receiver, be sure to use the

Trimble cable with proper over-current protection intended for this purpose, to avoid a safety hazard to the user
or damage to the product.

Charging the Lithium-ion batteries

The rechargeable Lithium-ion batteries are supplied partially charged. Charge the battery completely
before using it for the first time. If the battery has been stored for longer than three months, charge

SPS855 GNSS Modular Receiver Getting Started Guide 10

it before use.

WARNING – Charge and use the rechargeable Lithium-ion battery only in strict accordance with the instructions.

To prevent injury or damage:
– Discontinue charging a battery that gives off extreme heat or a burning odor.
– Never attempt to remove, replace, or repair the battery yourself.
– If the battery requires attention, send the receiver to an authorized Trimble Service Center.

The internal battery charges fully in 8 hours when connected to a suitable power source.

When the internal temperature of the receiver is greater than 50 °C (122 °F) or less than 5 °C (41 °F),
the internal battery charger stops charging and the receiver’s display shows Charger Disabled, Temp
Limited. However, the receiver will still draw its power from the external DC source, extending the
operating time in the field.

When the external DC voltage is not able to support the power drain, an X is displayed across the
battery status icon on the front panel display, which indicates that the internal charger is off.

Using the Lithium-ion battery as a Universal Power Supply (UPS)

The internal battery will only charge from an external power source as long as that source can
support the power drain, for example, an AC power adaptor. The receiver is supplied with an AC
power (also known as mains power) supply unit that recharges the battery inside the receiver when
it is connected through the adaptor to the modem port or the Lemo port. When you use the
receiver on large projects, from a permanent or semi-permanent base station location in a site
trailer, Trimble recommends that you use this power supply at all times to keep the internal battery
charged. This provides an uninterrupted power supply and will keep the site operational for more
than 10 hours after a power failure.

Keep all batteries on continuous charge when not in use. You can keep batteries on charge
indefinitely without damage to the receiver or to the batteries.

Removing the rechargeable Lithium-ion battery

The internal Lithium-ion battery should be removed only at an authorized Trimble Service Center. If
the battery is removed at an unauthorized service center, the remaining warranty on the product
will be void.

Storing the Lithium-ion battery

If you must store a Lithium-ion battery for long periods, make sure that it is fully charged before it is
stored, and that you charge it at least once every three months while it is stored.

Do not allow a battery that is in storage to discharge to below 5 V. A battery that reaches deep
discharge level (5 V or less) cannot be recharged and must be replaced. To protect a battery that is in
use from deep discharge, the receiver switches power sources or stops drawing power when the
battery pack discharges to 5.9 V.

All batteries discharge over time when not in use, and they discharge faster in colder temperatures.
Do not store the receiver at temperatures outside the range –40 °C to +70 °C (–40 °F to +158 °F).

SPS855 GNSS Modular Receiver Getting Started Guide 11

External power

Sources of external power include:

l

AC power

l

12 V vehicle battery

l

Trimble custom external battery pack

l

Generator power

l

Solar panel

The receiver uses an external power source in preference to its internal batteries. If the receiver is
not connected to an external power source, or if the external power supply fails, the internal
batteries are used.

While carrying out static measurements for postprocessed computations using the internal
memory, if no external power is supplied and the internal battery is drained, the receiver shuts
down. No data is lost and when power is restored, the receiver restarts in the same status as it was
when power was lost.

It is possible to turn off the internal battery using the web interface. In this case, when external
power is switched off, there is a limited time (30 seconds) before the unit turns off.

Supported power cables

Part Number Receiver

Connection

46125-20 7-pin Lemo 'Croc' clips Power from 12 V vehicle

59044-HH 7-pin Lemo Cable with DC

67384 7-pin Lemo Cable with DC

57167 26-pin Adapter with

57168 26-pin Adapter with

60789-00,
77070-00

65791-00,
78235-00

26-pin Cable with DC

26-pin Cable with DC

Power
Connection

plug

plug

DC plug

DC plug

plug

plug

Power Source Other Connectors

None

battery

Power to host devices
from AC adapter

Power to host devices
from AC adapter

Power from AC adapter USB(B) socket and Ethernet

Power from AC adapter Serial and Ethernet socket

Power from AC adapter 2 x Serial, Ethernet plug, USB(A)

Power from AC adapter 2 x Serial, Ethernet socket

Serial

Serial-to-serial for Moving Base
applications

socket

plug, 1PPS (BNC)

Note – SPS855 low voltage cut-offs:
Power applied through the Lemo connector models a standard 12.4 V lead acid battery. Shut­down voltage is temperature-compensated and is designed to prolong the life of a lead acid
battery and not place it into a deep discharge state.
Power applied through the 26-pin adaptor cable models a standard 11.1 V lithium-ion battery.

SPS855 GNSS Modular Receiver Getting Started Guide 12

Shut-down voltage is temperature-compensated and is designed to prolong the life of a lithium-ion
battery.
The external DC voltage supply can be used by the receiver if it is in the range stated by the label on
the receiver.

Connecting the receiver to a vehicle battery

WARNING – Use caution when connecting battery cable's clip leads to a vehicle battery. Do not allow any metal

object or jewelry to connect (short) the battery's positive (+) terminal to either the negative (-) terminal or the
metal of the vehicle connected to the battery. This could result in high current, arcing, and high temperatures,
exposing the user to possible injury.

WARNING – When connecting an external battery, such as a vehicle battery, to the receiver, be sure to use the

Trimble cable with proper over-current protection intended for this purpose, to avoid a safety hazard to the user
or damage to the product.

Front panel guide

Keypad and display

Item Feature Description

1 Power button Indicates if the receiver is on or off.

2 Buttons Used to turn on and configure the receiver.

3 Display The receiver has a Vacuum Fluorescent Display that enables you to

see how the receiver is operating and view the configuration

SPS855 GNSS Modular Receiver Getting Started Guide 13

Item Feature Description

settings.

4 Bluetooth antenna Location of the Bluetooth antenna.

Button operations

Use the buttons on the front panel to turn the receiver on and off and to check or change the
receiver settings.

Button Name Function

Power

Escape

Enter

Up

Down

Left

Right

Turns the receiver on and off and performs reset operations.

Returns to the previous screen or cancels changes being made on a screen.

Advances to the next screen or accepts changes made on a screen.

Moves the cursor between multiple fields on a screen or makes changes to an
editable field.

Moves the cursor between multiple fields on a screen or makes changes to an
editable field.

Moves the cursor between characters in a field that can be changed.

Moves the cursor between characters in a field that can be changed.

Power button operations

Press the Power button to turn the receiver on and off.

In addition, you can tap to return to the Home screen, or hold down to perform the
following operations:

To... Hold the Power button for... Notes

turn off the
receiver

clear the almanac,
ephemeris, and SV
information

reset the receiver
to its factory
defaults and the

two seconds The display shows a countdown timer. When the

display goes blank, release the

15 seconds The display shows a countdown timer. When the

display goes blank, continue to hold the
The display shows a countdown time to clear the
almanac and ephemeris. When the counter reaches 0,
release the

35 seconds The display shows a countdown timer. When the

display goes blank, continue to hold the
The display show a countdown to clear the almanac and

SPS855 GNSS Modular Receiver Getting Started Guide 14

Power

button.

Power

button.

Power

Power

button.

button.

To... Hold the Power button for... Notes

default application
file

ephemeris. When the counter reaches 0, continue to
hold the

Power

button. The display indicates a

countdown to resetting the receiver. When the counter

Power

button.

Power

button.

force the receiver
to power down

reaches 0, release the

at least 60 seconds If the reset method above does not work, use this

method to force the receiver to turn off. When the
Power LED goes off, release the

Status screens

The receiver has several view-only status screens that allow you to review the current settings of the
receiver. The status screens provide the following information:

l

Position solution and precisions

l

CMR and RTCM IDs or OmniSTAR satellite and link status

l

Base name and code

l

Latitude, longitude, and height

l

Antenna height

l

Horizontal and vertical precision

l

Receiver model and hardware version

l

Receiver firmware version

l

Receiver serial number

l

Receiver IP address

To access these screens from the Home screen, press or .

SPS855 GNSS Modular Receiver Getting Started Guide 15

SPS85x configuration screens

SPS855 GNSS Modular Receiver Getting Started Guide 16

SPS85x mode screens

SPS855 GNSS Modular Receiver Getting Started Guide 17

SPS85x status screens

SPS855 GNSS Modular Receiver Getting Started Guide 18

Configuring system settings

You can use the keypad and display of the receiver to configure the following settings:

l

Display language

l

Display and input units

l

Baud rate, parity, data bits, and stop bits for serial ports

l

Display power saver

l

AutoBase

l

Set position precisions

To access the system settings:

1.

In the Home screen, press . Use the Operation Mode screen to configure system settings or
mode settings, and to view the SV (satellite) status. Mode Settings is the default setting.

2.

Press . When the operation mode begins to flash, the receiver is in Edit mode and you can
change this setting.

3.

Press to change to System Setup.

4.

Press to accept the change.

5.

Press again.

6. Use the Display Language screen, if required, to change the language. Choose English, Finnish,

French, German, Italian, Spanish, or Swedish. Press to accept the change.

7.

Press again. Use the Display and Input Units screen, if required, to change the units to
Meters or US Feet.

8.

Press to accept the change.

9.

Press again. Use the Port Settings screen, if required, to change the port.

10.

Press to accept the change.

11.

Press again. Use the Screen Pwr Savr screen to choose On, Off, or Auto. If you use the Auto
setting, the screen turns off after 60 seconds of inactivity. The Power LED remains lit so that you
can tell if the receiver is on or off. If an error message appears, the screen comes back on. Press

to accept the change and then press again to move to the next screen.

12.

If you are using an SPS Modular RTK base station, the Autobase warning screen appears.

13.

Press to accept the change.

14.

Press again. When the Home screen appears, the system setup is complete.

SPS855 GNSS Modular Receiver Getting Started Guide 19

Turning off AutoBase technology

To turn off AutoBase technology, use either the receiver’s keypad and display or the web interface.

When AutoBase technology is off, you can establish a new base station position in the receiver using
the Edit Current or New Base (Here) menus. This does not automatically generate a new application
file, but changes the settings in the current application file. When the receiver is turned on again,
the most recent settings are always used.

To turn off AutoBase technology using the receiver:

1.

In the Home screen, press .

2.

Press . When the operation mode begins to flash, the receiver is in Edit mode and you can
change this setting.

3.

Press to change to System Setup.

4.

Press to accept the change.

5.

Press again. You start to scroll through options in the System Setup menu.

6.

Keep pressing until Autobase appears.

7.

Press . The setting On flashes.

8.

Press until it displays Off. Press to accept the change.

9.

Press again. The Active Appfile screen appears.

To change the application file:

l

Press to display START Appfile.

l

Press to show SAVE Appfile.

l

Press to show DELETE Appfile.

l

Press to show START Appfile.

SPS855 GNSS Modular Receiver Getting Started Guide 20

Signal tracking

This table shows the signal tracking capability for the SPS855 receiver:

Signal Type Class SPS855 (Construction and Marine)

GPS signals L1 Yes

L2 Yes

L2C Yes

L5 Optional

QZSS L1 C/A, L1C, L1 SAIF, L2C, L5 Yes (L5 optional)

GLONASS signals L1, L2 Optional

Galileo L1 CBOC, E5A, E5B, and E5AltBOC8 Optional

Compass B1, B2, B3 Optional

SBAScorrections WAAS Yes

EGNOS Yes

MSAS Yes

OmniSTAR corrections XP Yes

HP Yes

G2 Yes

VBS Yes

Beacon corrections MSK No

SPS855 GNSS Modular Receiver Getting Started Guide 21

Variable configuration options

This table lists the default options for the receiver:

Configuration Option SPS555H SPS855

Rover options

Precise horizontal - Optional

Precise vertical - Optional

Moving Base/Heading Yes Optional

Location RTK - Optional

RTCM DGPS - Optional

Moving Base RTK range limit 2.4 km None

Base options

Static RTK - Optional

Moving Base/Heading Yes Optional

RTCM DGPS - Optional

General options

Data logging - Optional

VRS support - Yes

Max data rate 20 Hz 20 Hz

Upgrading the receiver

When you purchase the upgrade after you have received the receiver, your Trimble dealer will
provide you with a code to change the receiver configuration.

The SPS855 can be upgraded as follows:

l

With GLONASS, L5, Galileo, Compass.

l

Models with 450 MHz UHF internal radio can be upgraded to 2 W transmission power, if it is
legally allowed in its country of use.

l

To allow internal data logging.

l

To Location RTK rover 10/10, Location RTK rover 10/2, Precision RTK rover, Precision RTK base,
Precision RTK base/rover, or Moving Base/Heading.

SPS855 GNSS Modular Receiver Getting Started Guide 22

Managing application files

You can use the front panel to manage application files in the receiver. You can see which
application file the receiver is currently using and then choose to make changes to it and save it,
load a different application file, or delete an application file.

To manage the application files, use the System Setupmenu. You can only manage application files
when the AutoBase feature is turned off.

To save an application file, configure all the settings you need through the front panel and then save
the file. When you save the file, the receiver provides a default filename, which you can change,
based on the currently set mode. For example:

Receiver mode Suggested application file name Notes

Base BASE01 Does not apply to the SPS555H receiver.

Heading HDG01

Moving Base MB01 Does not apply to the SPS555H receiver.

Rover ROV01 Does not apply to the SPS555H receiver.

Note – If you start an application file that is saved with AutoBase turned on in the file, then it turns
on AutoBase in the receiver, even if it was off before the file was loaded.

The following figure shows how application files are handled through the front panel of the receiver:

SPS855 GNSS Modular Receiver Getting Started Guide 23

Default receiver settings

All settings are stored in application files. The default application file, Default.cfg, is stored
permanently in the receiver, and contains the factory default settings. Whenever the receiver is
reset to its factory defaults, the current settings (stored in the current application file, Current.cfg)
are reset to the values in the default application file.

You cannot modify the default application file. However, you can create a power-up application file
so that the settings in this file can be applied immediately after the default application file,
overriding the factory defaults.

These settings are defined in the default application file.

Function Settings Factory default

SV Enable All SVs enabled

General Controls Elevation mask 10°

PDOP mask 7

RTK positioning mode Low Latency

Motion Kinematic

Serial Port 3 Baud rate 38,400

Format 8-None-1

Flow control None

Serial Port (Modem) 2 Baud rate 38,400

Format 8-None-1

Flow control None

Input Setup Station Any

NMEA/ASCII (all support messages) None

Streamed Output All types Off

Offset=00

RT17/Binary All ports Off

OmniSTAR Internal demodulator Off

Antenna Type Zephyr Geodetic Model 2

Height (true vertical) 0.00 m

Measurement method Antenna Phase Center

SPS855 GNSS Modular Receiver Getting Started Guide 24

Resetting the receiver to factory defaults

To reset the receiver to its factory defaults, do one of the following:

l

Press for 15 seconds.

l

In the GPS Configurator software, select Connect to Receiver and then click Reset Receiver in the
General tab.

l

In the Configuration Toolbox software, select the General tab and then click Reset Receiver.

For more information on the GPS Configurator and Configuration Toolbox software, refer to the
"Configuring the Receiver Settings" section of the Trimble SPS Series Receiver Help.

Default behavior

If a power-up application file is present in the receiver, its settings are applied immediately after the
default settings. This means you can use a power-up file to define your own set of defaults. The
factory defaults are also applied when you perform a full reset of the receiver because resetting the
receiver deletes the power-up files.

When starting any of the SPS receivers as a base station or rover receiver using the Trimble SCS900
site controller software or the HYDROpro software, the settings required for those operations are
automatically set and configured in that software. To change the receiver settings for special
applications or for use with third-party software, use the GPS Configurator software or the
Configuration Toolbox software.

Logging data

Data logging involves the collection of GNSS measurement data over a period of time at a static
point or points, and subsequent postprocessing of the information to accurately compute baseline
information. Data logging using receivers requires access to suitable GNSS postprocessing software
such as the Trimble Business Center software.

Postprocessed GNSS data is typically used for control network measurement applications and
precise monitoring. GNSS measurement data is collected over a period of time at a static point or
points and then postprocessed to accurately compute baseline information.

By default, the Data Logging option is turned off. For information on how to enable the Data
Logging option, and the required postprocessing software options, contact your Trimble dealer.

Logging data after a power loss

If power is unexpectedly lost while the receiver is logging data, the receiver tries to return to the
state it was in immediately before the power loss. The receiver does not reset itself to default
settings.

If the receiver was logging data when power was lost, it resumes logging data when power is
restored.

SPS855 GNSS Modular Receiver Getting Started Guide 25

Adding radio frequencies

Adding frequencies for the 450 MHz internal radio using the WinFlash utility

If your receiver has the optional internal radio installed, you can use the WinFlash utility to add
receiving frequencies to the default list.

You can also use the web interface to add and manage receiver 450 MHz frequencies.

If you purchase a transmit upgrade (after initial purchase), the broadcast frequencies must be
programmed using a .set file obtained from a Trimble service provider.

1. Start the WinFlash utility. The Device Configuration screen appears.

2. From the Device type list, select the receiver.

3. From the PC serial port field, select the serial (COM) port on the computer that the receiver is
connected to.

4.

Click Next.

The Operation Selection screen appears. The Operations list shows all of the supported
operations for the selected device. A description of the selected operation is shown in the
Description field.

5.

Select Configure Radio and then click Next.

The Frequency Selection dialog appears.

6.

In the Wireless Format group, select the appropriate channel and wireless mode. The wireless
mode must be the same for all radios in your network.

7. In the Specify Frequency field, enter the frequency you require.

8.

Click Add. The new frequency appears in the Selected Frequencies list.

Note – The frequencies that you program must conform to the channel spacing and minimum
tuning requirements for the radio. To view this information, click Radio Info. You may select
either 12.5 or 25 kHz channel spacing. All radios in your network must use the same channel
spacing.

9.

When you have configured all the frequencies you require, click OK.

The WinFlash utility updates the receiver radio frequencies and then restarts the receiver.

Note – You can only configure receive frequencies. The FCC-approved transmit frequencies
must be specified and configured by Trimble.

Setting UHF reception radio frequencies using the web interface

To enter your own Receive (Rx) frequency using the web interface:

1. Select the Radio menu.

2. Select the Frequency Management submenu.

SPS855 GNSS Modular Receiver Getting Started Guide 26

3. Make a note of the details shown in the Frequency range and Tuning step fields. Any new
frequencies must be within the range shown and must also be a multiple of the KHz shown in
the Tuning step field.

4. Select the Add Channel option and then enter the new channel frequency.

5. Click OK.

To delete a channel frequency:

1. Select the Delete channel option.

2. Select a channel to delete from the list that appears.

You cannot add or delete Transmit (Tx) channels using the web interface.

SPS855 GNSS Modular Receiver Getting Started Guide 27

Troubleshooting receiver issues

This section describes some possible receiver issues, possible causes, and how to solve them. Please
read this section before you contact Technical Support.

The receiver does not turn on

Possible cause Solution

External power is too low. Check the charge on the external power supply, and check the fuse if

applicable. If required, replace the battery.

Internal power is too low. Do the following:

l

Check the charge on the internal batteries and replace if
required.

l

Ensure battery contacts are clean.

External power is not properly
connected.

Do the following:

l

Check that the Lemo connection is seated properly.

l

Check for broken or bent pins in the connector.

Faulty external power cable. Do the following:

l

Try a different cable.

l

Check pinouts with multimeter to ensure internal wiring is
intact.

The receiver is not tracking any satellites

Possible cause Solution

The GNSS antenna does not have
clear line of sight to the sky.

The cable between the receiver and
the GNSS antenna is damaged.

The cable connections at receiver or
antenna are not tightly seated, or
are connected incorrectly.

Ensure that the antenna has a clear line of sight.

Replace the cable.

Check all cable connections.

The receiver does not log data

Possible cause Solution

Insufficient memory in the internal
memory.

The receiver is tracking fewer than

Delete old files using the GPS Configurator software, or press for

30 seconds.

l

Wait until the SV Tracking LED is flashing slowly. Use the SCS900

SPS855 GNSS Modular Receiver Getting Started Guide 28

Possible cause Solution

four satellites.

The data logging option is not
enabled.

software.

l

Go to the SkyPlot screen and press Ctrl+M to access the current
elevation mask settings. Reduce the mask value to make more
satellites available.

l

The default mask setting for receiver is 10° above the horizon.
Change the value to a lower setting temporarily while you are
waiting for a better constellation availability.

Check the original purchase order or the receiver configuration using
the WinFlash utility. If data logging is not enabled on the receiver, you
can order the option from your local Trimble Site Positioning Systems
dealer, and upgrade the receiver using the WinFlash utility.

The receiver is not responding

Possible cause Solution

The receiver needs a soft reset. Turn off the receiver and then turn it back on again.

The receiver needs a full reset. Press for 30 seconds.

The receiver cannot be set up as a base station using the SCS900 soft­ware

Possible cause Solution

The SPS Modular receiver may have
been purchased as a rover receiver
rather than with the optional base
station capability.

Ask your local dealer to check the Option Bit settings, else check the
setting yourself using the WinFlash utility. If required, upgrade the
receiver.

SPS855 GNSS Modular Receiver Getting Started Guide 29

Glossary

1PPS

almanac

AutoBase

base station

beacon

Pulse-per-second. Used in hardware timing. A pulse is generated in conjunction
with a time stamp. This defines the instant when the time stamp is applicable.

A file that contains orbit information on all the satellites, clock corrections, and
atmospheric delay parameters. The almanac is transmitted by a GNSS satellite to
a GNSS receiver, where it facilitates rapid acquisition of GNSS signals when you
start collecting data, or when you have lost track of satellites and are trying to
regain GNSS signals.

The orbit information is a subset of the ephemeris/ephemerides data.

AutoBase technology uses the position of the receiver to automatically select the
correct base station; allowing for one button press operation of a base station. It
shortens setup time associated with repeated daily base station setups at the
same location on jobsites.

Also called reference station. In construction, a base station is a receiver placed at
a known point on a jobsite that tracks the same satellites as an RTK rover, and
provides a real-time differential correction message stream through radio to the
rover, to obtain centimeter level positions on a continuous real-time basis. A
base station can also be a part of a virtual reference station network, or a
location at which GNSS observations are collected over a period of time, for
subsequent postprocessing to obtain the most accurate position for the location.

Source of RTCM DGPS corrections transmitted from coastal reference stations in
the 283.5 to 325.0 kHz range.

BINEX

broadcast server

carrier

carrier frequency

carrier phase

cellular modems

CMR/CMR+

BInary EXchange format. BINEX is an operational binary format standard for
GPS/GLONASS/SBAS research purposes. It is designed to grow and allow
encapsulation of all (or most) of the information currently allowed for in a range
of other formats.

An Internet server that manages authentication and password control for a
network of VRS servers, and relays VRS corrections from the VRS server that you
select.

A radio wave having at least one characteristic (such as frequency, amplitude, or
phase) that can be varied from a known reference value by modulation.

The frequency of the unmodulated fundamental output of a radio transmitter.
The GPS L1 carrier frequency is 1575.42 MHz.

Is the cumulative phase count of the GPS or GLONASS carrier signal at a given
time.

A wireless adaptor that connects a laptop computer to a cellular phone system
for data transfer. Cellular modems, which contain their own antennas, plug into a
PC Card slot or into the USB port of the computer and are available for a variety
of wireless data services such as GPRS.

Compact Measurement Record. A real-time message format developed by
Trimble for broadcasting corrections to other Trimble receivers. CMR is a more
efficient alternative to RTCM.

CMRx

A real-time message format developed by Trimble for transmitting more satellite

SPS855 GNSS Modular Receiver Getting Started Guide 30

corrections resulting from more satellite signals, more constellations, and more
satellites. Its compactness means more repeaters can be used on a site.

Compass

covariance

datum

The BeiDou Navigation Satellite System (Compass) is a Chinese satellite navigation
system.

The first BeiDou system (known as BeiDou-1), consists of three satellites and has
limited coverage and applications. It has been offering navigation services mainly
for customers in China and from neighboring regions since 2000.

The second generation of the system (known as Compass or BeiDou-2) consists
of 35 satellites. It became operational with coverage of China in December 2011
with 10 satellites in use. It is planned to offer services to customers in Asia­Pacific region by 2012 and the global system should be finished by 2020.

A statistical measure of the variance of two random variables that are observed
or measured in the same mean time period. This measure is equal to the
product of the deviations of corresponding values of the two variables from their
respective means.

Also called geodetic datum. A mathematical model designed to best fit the geoid,
defined by the relationship between an ellipsoid and, a point on the topographic
surface, established as the origin of the datum. World geodetic datums are
typically defined by the size and shape of an ellipsoid and the relationship
between the center of the ellipsoid and the center of the earth.

Because the earth is not a perfect ellipsoid, any single datum will provide a
better model in some locations than in others. Therefore, various datums have
been established to suit particular regions.

For example, maps in Europe are often based on the European datum of 1950
(ED-50). Maps in the United States are often based on the North American
datum of 1927 (NAD-27) or 1983 (NAD-83).

All GPS coordinates are based on the WGS-84 datum surface.

deep discharge

DGPS

differential correction

differential GPS

DOP

Withdrawal of all electrical energy to the end-point voltage before the cell or
battery is recharged.

See real-time differential GPS.

Differential correction is the process of correcting GNSS data collected on a

rover with data collected simultaneously at a base station. Because the base

station is on a known location, any errors in data collected at the base station can
be measured, and the necessary corrections applied to the rover data.

Differential correction can be done in real-time, or after the data is collected by

postprocessing.

See real-time differential GPS.

Dilution of Precision. A measure of the quality of GNSS positions, based on the
geometry of the satellites used to compute the positions. When satellites are
widely spaced relative to each other, the DOP value is lower, and position
accuracy is greater. When satellites are close together in the sky, the DOP is
higher and GNSS positions may contain a greater level of error.

PDOP (Position DOP) indicates the three-dimensional geometry of the satellites.

Other DOP values include HDOP (Horizontal DOP) and VDOP (Vertical DOP),

SPS855 GNSS Modular Receiver Getting Started Guide 31

which indicate the accuracy of horizontal measurements (latitude and longitude)
and vertical measurements respectively. PDOP is related to HDOP and VDOP as
follows: PDOP² = HDOP² + VDOP².

dual-frequency GPS

EGNOS

elevation mask

ellipsoid

EHT

ephemeris/ephemerides

epoch

A type of receiver that uses both L1 and L2 signals from GPS satellites. A dual­frequency receiver can compute more precise position fixes over longer
distances and under more adverse conditions because it compensates for
ionospheric delays.

European Geostationary Navigation Overlay Service. A Satellite-Based
Augmentation System (SBAS) that provides a free-to-air differential correction
service for GNSS. EGNOS is the European equivalent of WAAS, which is available
in the United States.

The angle below which the receiver will not track satellites. Normally set to 10
degrees to avoid interference problems caused by buildings and trees,
atmospheric issues, and multipath errors.

An ellipsoid is the three-dimensional shape that is used as the basis for
mathematically modeling the earth’s surface. The ellipsoid is defined by the
lengths of the minor and major axes. The earth’s minor axis is the polar axis and
the major axis is the equatorial axis.

Height above ellipsoid.

A list of predicted (accurate) positions or locations of satellites as a function of
time. A set of numerical parameters that can be used to determine a satellite’s
position. Available as broadcast ephemeris or as postprocessed precise
ephemeris.

The measurement interval of a GNSS receiver. The epoch varies according to the
measurement type: for real-time measurement it is set at one second; for
postprocessed measurement it can be set to a rate of between one second and
one minute. For example, if data is measured every 15 seconds, loading data
using 30-second epochs means loading every alternate measurement.

feature

firmware

Galileo

GHT

GIOVE

GLONASS

A feature is a physical object or event that has a location in the real world, which
you want to collect position and/or descriptive information (attributes) about.
Features can be classified as surface or non-surface features, and again as points,
lines/breaklines, or boundaries/areas.

The program inside the receiver that controls receiver operations and hardware.

Galileo is a GNSS system built by the European Union and the European Space
Agency. It is complimentary to GPS and GLONASS.

Height above geoid.

Galileo In-Orbit Validation Element. The name of each satellite for the European
Space Agency to test the Galileo positioning system.

Global Orbiting Navigation Satellite System. GLONASS is a Soviet space-based
navigation system comparable to the American GPS system. The operational
system consists of 21 operational and 3 non-operational satellites in 3 orbit
planes.

SPS855 GNSS Modular Receiver Getting Started Guide 32

GNSS

Global Navigation Satellite System.

GSOF

HDOP

IBSS

L1

L2

L2C

L5

General Serial Output Format. A Trimble proprietary message format.

Horizontal Dilution of Precision. HDOP is a DOP value that indicates the accuracy
of horizontal measurements. Other DOP values include VDOP (vertical DOP) and

PDOP (Position DOP).

Using a maximum HDOP is ideal for situations where vertical precision is not
particularly important, and your position yield would be decreased by the
vertical component of the PDOP (for example, if you are collecting data under
canopy).

Internet Base Station Service. This Trimble service makes the setup of an
Internet-capable receiver as simple as possible. The base station can be
connected to the Internet (cable or wirelessly). To access the distribution server,
the user enter a password into the receiver. To use the server, the user must
have a Trimble Connected Community site license.

The primary L-band carrier used by GPS and GLONASS satellites to transmit
satellite data.

The secondary L-band carrier used by GPS and GLONASS satellites to transmit
satellite data.

A modernized code that allows significantly better ability to track the L2
frequency.

The third L-band carrier used by GPS satellites to transmit satellite data. L5 will
provide a higher power level than the other carriers. As a result, acquiring and
tracking weak signals will be easier.

Location RTK

Mountpoint

Moving Base

MSAS

multipath

NMEA

Some applications such as vehicular-mounted site supervisor systems do not
require Precision RTK accuracy. Location RTK is a mode in which, once initialized,
the receiver will operate either in 10 cm horizontal and 10 cm vertical accuracy,
or in 10 cm horizontal and and 2 cm vertical accuracy.

Every single NTripSource needs a unique mountpoint on an NTripCaster. Before
transmitting GNSS data to the NTripCaster, the NTripServer sends an assignment
of the mountpoint.

Moving Base is an RTK positioning technique in which both reference and rover
receivers are mobile. Corrections are sent from a “base” receiver to a “rover”
receiver and the resultant baseline (vector) has centimeter-level accuracy.

MTSAT Satellite-Based Augmentation System. A Satellite-Based Augmentation
System (SBAS) that provides a free-to-air differential correction service for GNSS.
MSAS is the Japanese equivalent of WAAS, which is available in the United States.

Interference, similar to ghosts on an analog television screen, that occurs when
GNSS signals arrive at an antenna having traversed different paths. The signal
traversing the longer path yields a larger pseudorange estimate and increases
the error. Multiple paths can arise from reflections off the ground or off
structures near the antenna.

National Marine Electronics Association. NMEA 0183 defines the standard for
interfacing marine electronic navigational devices. This standard defines a

SPS855 GNSS Modular Receiver Getting Started Guide 33

number of 'strings' referred to as NMEA strings that contain navigational details
such as positions. Most Trimble GNSS receivers can output positions as NMEA
strings.

NTrip Protocol

NTripCaster

NTripClient

NTripServer

NTripSource

Networked Transport of RTCM via Internet Protocol (NTrip) is an application-level
protocol that supports streaming Global Navigation Satellite System (GNSS) data
over the Internet. NTrip is a generic, stateless protocol based on the Hypertext
Transfer Protocol (HTTP). The HTTP objects are extended to GNSS data streams.

The NTripCaster is basically an HTTP server supporting a subset of HTTP
request/response messages and adjusted to low-bandwidth streaming data. The
NTripCaster accepts request messages on a single port from either the
NTripServer or the NTripClient. Depending on these messages, the NTripCaster
decides whether there is streaming data to receive or to send.

Trimble NTripCaster integrates the NTripServer and the NTripCaster. This port is
used only to accept requests from NTripClients.

An NTripClient will be accepted by and receive data from an NTripCaster, if the
NTripClient sends the correct request message (TCP/UDP connection to the
specified NTripCaster IP and listening port).

The NTripServer is used to transfer GNSS data of an NTripSource to the
NTripCaster. An NTripServer in its simplest setup is a computer program running
on a PC that sends correction data of an NTripSource (for example, as received
through the serial communication port from a GNSS receiver) to the NTripCaster.

The NTripServer - NTripCaster communication extends HTTP by additional
message formats and status codes.

The NTripSources provide continuous GNSS data (for example, RTCM-104
corrections) as streaming data. A single source represents GNSS data referring to
a specific location. Source description parameters are compiled in the source­table.

OmniSTAR

PDOP

POE

postprocessing

QZSS

The OmniSTAR HP/XP service allows the use of new generation dual-frequency
receivers with the OmniSTAR service. The HP/XP service does not rely on local
reference stations for its signal, but utilizes a global satellite monitoring network.
Additionally, while most current dual-frequency GNSS systems are accurate to
within a meter or so, OmniSTAR with XP is accurate in 3D to better than 30 cm.

Position Dilution of Precision. PDOP is a DOP value that indicates the accuracy of
three-dimensional measurements. Other DOP values include VDOP (vertical
DOP) and HDOP (Horizontal Dilution of Precision).

Using a maximum PDOP value is ideal for situations where both vertical and
horizontal precision are important.

Power Over Ethernet. Provides DC power to the receiver using an Ethernet
cable.

Postprocessing is the processing of satellite data after it is collected, in order to
eliminate error. This involves using computer software to compare data from the
rover with data collected at the base station.

Quasi-Zenith Satellite System. A Japanese regional GNSS eventually consisting of
three geosynchronous satellites over Japan.

SPS855 GNSS Modular Receiver Getting Started Guide 34

real-time differential
GPS

Also known as real-time differential correction or DGPS. Real-time differential
GPS is the process of correcting GPS data as you collect it. Corrections are
calculated at a base station and then sent to the receiver through a radio link. As
the rover receives the position it applies the corrections to give you a very
accurate position in the field.

Most real-time differential correction methods apply corrections to code phase
positions.

While DGPS is a generic term, its common interpretation is that it entails the use
of single-frequency code phase data sent from a GNSS base station to a rover
GNSS receiver to provide sub-meter position accuracy. The rover receiver can
be at a long range (greater than 100 kms (62 miles)) from the base station.

rover

Roving mode

RTCM

RTK

SBAS

signal-to-noise ratio

A rover is any mobile GNSS receiver that is used to collect or update data in the
field, typically at an unknown location.

Roving mode applies to the use of a rover receiver to collect data, stakeout, or
control earthmoving machinery in real time using RTK techniques.

Radio Technical Commission for Maritime Services. A commission established to
define a differential data link for the real-time differential correction of roving
GNSS receivers. There are three versions of RTCM correction messages. All
Trimble GNSS receivers use Version 2 protocol for single-frequency DGPS type
corrections. Carrier phase corrections are available on Version 2, or on the
newer Version 3 RTCM protocol, which is available on certain Trimble dual­frequency receivers. The Version 3 RTCM protocol is more compact but is not as
widely supported as Version 2.

real-time kinematic. A real-time differential GPS method that uses carrier phase
measurements for greater accuracy.

Satellite-Based Augmentation System. SBAS is based on differential GPS, but
applies to wide area (WAAS/EGNOS/MSAS) networks of reference stations.
Corrections and additional information are broadcast using geostationary
satellites.

SNR. The signal strength of a satellite is a measure of the information content of
the signal, relative to the signal’s noise. The typical SNR of a satellite at 30°
elevation is between 47 and 50 dBHz.

skyplot

SNR

Source-table

The satellite skyplot confirms reception of a differentially corrected GNSS signal
and displays the number of satellites tracked by the GNSS receiver, as well as
their relative positions.

See signal-to-noise ratio.

The NTripCaster maintains a source-table containing information on available
NTripSources, networks of NTripSources, and NTripCasters, to be sent to an
NTripClient on request. Source-table records are dedicated to one of the
following:

l

data STReams (record type STR)

l

CASters (record type CAS)

l

NETworks of data streams (record type NET)

SPS855 GNSS Modular Receiver Getting Started Guide 35

All NTripClients must be able to decode record type STR. Decoding types CAS and
NET is an optional feature. All data fields in the source-table records are
separated using the semicolon character.

triple frequency GPS

UTC

VRS

WAAS

A type of receiver that uses three carrier phase measurements (L1, L2, and L5).

Universal Time Coordinated. A time standard based on local solar mean time at
the Greenwich meridian.

Virtual Reference Station. A VRS system consists of GNSS hardware, software,
and communication links. It uses data from a network of base stations to provide
corrections to each rover that are more accurate than corrections from a single
base station.

To start using VRS corrections, the rover sends its position to the VRS server. The
VRS server uses the base station data to model systematic errors (such as
ionospheric noise) at the rover position. It then sends RTCM correction messages
back to the rover.

Wide Area Augmentation System. WAAS was established by the Federal Aviation
Administration (FAA) for flight and approach navigation for civil aviation. WAAS
improves the accuracy and availability of the basic GNSS signals over its coverage
area, which includes the continental United States and outlying parts of Canada
and Mexico.

The WAAS system provides correction data for visible satellites. Corrections are
computed from ground station observations and then uploaded to two
geostationary satellites. This data is then broadcast on the L1 frequency, and is
tracked using a channel on the GNSS receiver, exactly like a GNSS satellite.

Use WAAS when other correction sources are unavailable, to obtain greater
accuracy than autonomous positions. For more information on WAAS, refer to
the FAA website at http://gps.faa.gov.

The EGNOS service is the European equivalent and MSAS is the Japanese
equivalent of WAAS.

WGS-84

World Geodetic System 1984. Since January 1987, WGS-84 has superseded
WGS-72 as the datum used by GPS.

The WGS-84 datum is based on the ellipsoid of the same name.

SPS855 GNSS Modular Receiver Getting Started Guide 36