Foif A20 User Manual

A20 GNSS Receiver

User Manual

Suzhou FOIF Co.,Ltd

Version 1.0

System from FOIF! GNSS has revolutionized control surveys, topographic data collection

and construction surveying. Purchasing the right tools for a professional job is essential in

today's competitive business environment. Learning to put these tools to work quickly and

efficiently will be the focus of the present manual. Compared with other GNSS products,

exclusive multi-constellation (GPS+GLONASS+SBAS) capabilities. In addition because

it's easy to use, you will be able to focus on your job.

for all your GNSS survey operations!

Congratulations! You have just acquired the latest dual-frequency A20 GNSS Surveying

Introduction

A20 is more compact and lightweight while integrating more technology, such as the

No more cables, no more clip-on modules: A20 will be the reliable tool you are expecting

1 Summary
2 Unpacking the Container

2.1 Container Contents

2.2 Components of the PS236 Controller

3 Setting Up Receivers

3.1 Base Station

3.2 Setting Up Base Station by External Radio

3.3 External Radio

3.4 Power Amplifer

3.5 Rover Station

4 General Introduction

4.1 Nomenclature

4.2 Displayed Panel and Keyboard

4.3 Battery

5 Receiver Operation

Contents

5.1 Button

5.2 LED Indicating Lights

1
3
3
5
6

6
8
9

11

12

16
16
18
19
20
20
23

Safety Information

3.6 Measuring the A ntenna Heights

13

3.7 Controller Connecting

15

6 Static Surveying

6.1 Process

6.2 Data Downloading and Format Converting

6.3 Ways of Outdoors Working for Static Surveying

6.4 GPS Network

35
35
35
38
39

46
46
46

47
48

7 Specifications

7.1 Physical Specifications

7.2 Positioning Specifications

7.3 Technical Specifications

7.4 Technical Specifications for Controller

5.3 Displayed Menu

24

Safety Information

This manual describes the A20 GNSS Receiver.

Before you use your receiver make sure that you have read and understood this manual, as

well as all safety requirements.

WARNING

CAUTION

Ignoring this indication and making an operation error could

possibly result in death or serious injury to the operator.

Ignoring this indication and making an operation error could

possibly result in personal injury or property damage.

Regulations and safety

The receivers contain integra Bluetooth wireless technology, and may also send radio

signal through the antenna of an internal radio-modern, or through an externally-connected

data communication radio. Regulations regarding the use of the 460MHz 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 FOIF dealer. Bluetooth operates in license-free bands.

Exposure to radio frequency radiation

For radio (410~430MHz/430~450MHz/450~470MHz)

It is safety. Exposure to RF energy is an important safety consideration. Proper use of this

radio modem results in exposure below government limits.

The following precautions are recommended:

lDO NOT operate the transmitter when someone is within 20cm of the antenna.

lDO NOT collocate (place within 20cm) the radio antenna with any other transmitting

lDO NOT operate the transmitter unless all RF connectors are secure and any open

connectors are properly terminated.

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

lAll equipment must be properly grounded according to FOIF installation instructions for

safe operation.

lAll equipment should be serviced only by a qualified technician.

For GSM radio

CAUTION

- For your own safety, always observe the precautions listed here.

- Always maintain a minimum separation distance of 20cm between

yourself and the radiating antenna on the radio-modem.

- Do not collocate (place within 20cm) the radio antenna with any

other transmitting antenna.

antenna.

For Bluetooth radio

The radiated output power of the internal Bluetooth wireless radio is far below radio fre-

quency exposure limits. Nevertheless, the wireless radio shall be used in such a manner

that the FOIF receiver is 20cm 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. FOIF therefore believes 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

Installing antennas

CAUTION

- For your own safety, always observe the precautions listed here.

- Always maintain a minimum separation distance of 20cm between

yourself and the radiating antenna.

- Do not collocate (place within 20cm) the radio antenna with any

other transmitting antenna.

turning on the wireless radio.

This device has been designed to operate with the antennas listed below.

UHF Antennas not included in this list, or that have a gain greater than 5dBi, 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 460 MHz radio are 0dBi and

5dBi whip antennas.

The antenna that can be used with the GSM radio is the 0dBi whip antenna.

To reduce potential radio interference to other users, the antenna type and its gain should

be so chosen that the equivalent isotropic ally radiated power is not more than that permitted

for successful communication.

Rechargeable Lithium-ion batteries

These receivers use a rechargeable Lithium-ion battery.

WARNING

- Do not damages 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 sun-

- 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 is

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

light.

WARNING

- Charge and use the rechargeable Lithium-ion battery only in strict

accordance with the instructions. Charging or using the battery in

unauthorized equipment can cause an explosion or fire, and can

result in personal injury and/or equipment damage.

To prevent injury or damage:

- Do not charge or use the battery of it appears to be damaged or

- Charge the Lithium-ion battery only in FOIF product that is spe-

cified to charge it. Be sure to follow all instructions that are pro-

vided with the battery charger.

- Discontinue charging a battery that gives off extreme heat or a burn-

ing odor.

- Use the battery only in FOIF equipment that is specified to use it.

- Use the battery only for its intended use and according to the

instructions in the product documentation.

Other Warning

WARNING

- Operating or storing the receiver outside the specified temperature

range can damage it.

For more information, refer to 9. SPECIFICATION.

leaking.

A20 is regarded as an highly integrated, semi-open structure and modular designed RTK

system independently researched by FOIF. GNSS antenna,data link, GPRS/CDMA,Li-Ion

which is convenient in the products maintainance and upgrade. Stable industry standard

two data transmission ways (GPRS/CDMA, data Link),we can use 3G function of the

With high accuracy, fast tracking function of inner GNSS mainboard,A20 can track the

satellite signal as more as 220 channels simultaneously.

Highly sealed, waterproof, dustproof, shockproof, low power consumption are its basic

inspecting rules. With super and weatherable OLED screen built on A20 receiver, the real

1 Summary

battery, memory device, bluetooth etc. are all focused in one receiver. Moreover, GNSS

antenna, datalink and battery are independently modules which are easy to replace thus

handheld for A20 has inner or external GPS antenna and camera for optional function to

upgrade this handheld to a GIS collector. 3G memory device is also optional for the hand-

held, thus can further upgrade to a highly accurate GIS collector. Meanwhile, besides the

mobile phone to do the RTK job, in this way, we can say A20 has already existed in 3G

time information of the receiver can be shown on the screen. 4 lights and 6 buttons are

easily used to set the receiver, and the voice aided is helpful to the outdoors surveying.

Downloading and backups of the static data could be convenient because of the inner SD

slot, thus resolves your trouble for the insuffcient memory.

A20 User Manual

1

period.

is no problem but also for the compatability in the CORS of other companies. In order to

fulfill the characteristic of compatability in A20, inner radio can easily be upgraded to be

compatible with GNSS products of other companies in the RTK field. The electric power

design for A20 is also very advanced, large capacity of Li-Ion batteries(4400mAh) can

on both external and internal charging ways. A20 can also be used by external DC power

A20 is widely used for control survey,engineering survey,topography survey,GIS,boundries

location, area survey, deformation monitoring etc. And from the education subjects based

also be used on the total station (810 series) made by FOIF. These batteries are depended

on GNSS products, you can also find A20.

A20 User Manual

2

Due to its advanced compatability, static surveying with GNSS products of other companies

(7-18V).

2 Unpacking the Container

2.1 Container Contents

The main components required for the cableless GNSS real-time system are combined in

one transport container.

A Base

B Charger (car)

A

B

C

D

E

F

G

H

I

J

K

L

M

N

C Charging cable (1.5m)

D Transferring cable

E RF cable (2.8m)

F Connecting line (RS232)

G Connecting cable between

storage and receiver

H Battery

I Charger

J Tape

K Plate

L Radio (Optional)

M Connector

N UHF antenna

Base Container

Description

Container for
A20

and delivered
accessories
part 1 of 2

A20 User Manual

3

A

B

C

D

E

F

G

H

I

J

K

Rover Container

A Rover

B Charger for controller

C Connecting line for controller

D Battery

E Charger

F Tape

G Connector

H PS236

I Bracket

J Charger (car)

K UHF antenna

L

M

L Pole

M Enhanced UHF antenna

Detailed information can check from A20 equipment list.

Container for
A20

and delivered
accessories
part 2 of 2

A20 User Manual

4

a) Microsoft Windows Mobile 6.1 OS
b) 3.5inch transflective sunlight readable LCD
c) Embedded high sensitivity GPS receiver
d) MIL-STD-810G and IP67 compliance
e) Long battery life provides all-day power
f) 3G function is supported

2.2 Components of the PS236 Controller

PS236

A20 User Manual

5

Base

Picture showing
real-time
base station
setup

Choose a suitable place for your base station setting up.

1) The place for base station setting up should be wide opened and easy to receive the

2) Higher place would be better for setting up, thus signal of UHF is easy to receive. If

is far from base, then the enhanced antenna should be raised by using bipod.

signal of satellites.

3) Base should be far away from the high power WiFi objects,e.g. radio,

MWS etc. Distance between them needs to be more than 200m. And

less than 50m from power lines is also forbidden to set up base.

Process:

1. Set up the tripod mount and level the tribrach onto the tripod.

2. Check that the tribrach is correctly centred over the marker.

3. Place and lock the receiver on the tribrach.

4. Check that the tribrach is still correctly positioned and leveled.

5. Choose external radio module from FOIF Survey_GPS software.

6. Fix the radio beside tripod, using cable FG-DB9-M to do the

*

7. Fix enhanced UHF antenna.

connection work between radio and receiver.

A20 User Manual

3 Setting Up Receivers

3.1 Base Station

6

rover

Notice:

lWhen plugging in an cable with ODU plug, make sure that the red dots on the receiver

port and the cable connector line up. Do not use force to plug cables in, as this may da-

mage the connector pins.

lWhen disconnecting an cable with ODU plug, grasp the cable by the sliding collar or

lanyard and then pull the cable connector straight out of the port. Do not twist the

connector or pull on the cable itself.

lTo securely connect a TNC antenna, align the antenna connector with the receiver

receptacle and then thread the antenna connector onto the receptacle until it is snug.

lAvoid the following sources of electrical and magnetic noise:

a) Gasoline engines (spark plugs) b) Televisions and PC monitors

c) Alternators and generators d) Electric motors

e) Equipment with DC-to-AC converters f) Fluorescent lights

g) Switching power supplies

lAvoid exposure to extreme environmental conditions, including:

a) Water

b) Heat than 65

c) Cold less than -30

d) Corrosive fluids and gases

8. Connecting radio and storage with cable FDL-1-1 and cable FDL-1-2.

*

*

check from A20 equipment list

A20 User Manual

7

Two tripods
supported

A20 User Manual

3.2 Setting Up Base Station by External Radio

8

Channel
0~9&A~F

Channel
displayed

Signal
light

Power

Power
light

Data input
&battery supplied

Heat sink

Antenna port

Button for
power setting

Frontal panel (buttons and channel displayed )

Back panel (ports detailed)

PCC radio

A20 User Manual

9

3.3 External Radio

Notice:

1) Connection should be tight between every part(cable,radio,receiver) to com-

firm the successful data transferring.

2) Storage battery used should distinguish the positive and negative poles to avoid

the electric short circuit.

3) Suggested brand of storage battery is Panasonic, other brands such as camel,

fengfan ect. are also accepted as long as the output voltage is 12V and power

comsumption is not less than 17Ah.

4) 5m pole is suggested in raising the UHF antenna for better signals.

5) Distance between UHF antenna and A20 should be more than 3m.

6) Considering the safety of yours, A20 is not suggested to be used at the weather

of thunder or storms.

A20 User Manual

10

A20 User Manual

11

Function:

Power Amplifer can enlarge transferring

Port for ANT

PWR Light

DATA Light

PWR Port
Port for RF.IN

distance which is the same function as

external radio, but should work together

with A20 which has inner emitting radio.

Because A20 has many Product Numbers to

choose for deciding its configuration. So if

your A20 doesn

then Power Amplifer is not suitable, only

external radio.

t have inner emitting radio,

Notice:

1) Connection should be tight between every part(cable,radio,receiver) to comfirm

the successful data transferring.

2) Storage battery used should distinguish the positive and negative poles to avoid

the electric short circuit.

3) Comfirm that the antenna is connecting with the Power Amplifer before emitting

4) Finish working, make sure to stop emitting the data firstly, then remove the cable.

3) and 4) are all benefic for protecting the Power Amplifer.

Made by FOIF

the data.

3.4 Power Amplifer

receiver

UHF antenna

telescopic pole

controller

bracket

Notice:

1. If telescopic pole is used, height of receiver

can be got directlly from the pole.

2. Comfirm that connection between bracket

and controller is tight to avoid that controller

dropping to the ground.

3. If network is used, then UHF antenna does not

need to fix on A20.

Picture showing
real-time
rover station
setup

A20 User Manual

Process:

1. Thread the receiver onto the pole.

2. Attach the controller bracket to the pole.

3. Insert the controller into the bracket.

3.5 Rover Station

12

3.6 Measuring the Antenna Heights

3.6.1 Measuring the Antenna Heights for a Tripod Setup

Ways: Pay attention to the buckle of black rubber fixing around the receiver, use your

tapeline from the buckle to the point where your base is setting up, thus the reading

on tapeline is the height of base.

Height

of

DPCA

vertical

(slant)

Height of DPCA=Vertical+h0

A20 User Manual

13

Measuring the
antenna heights,
a quick overview

Parameter of A20 antenna: h0=(L1+L2)/2-h 54.3mm R0=R=110mm

3.6.2 Measuring the Antenna Heights for a Pole Setup

Height of rover=pole(2m)+h0

Considering the normal height of pole is 2m, so while setting the rover, you just only

choose vertical height and enter 2m , which is also the default choice, h0 could be

add automatically by software (FOIF Survey_GPS). If telescopic pole is used, then 2m

should be changed to the actual height of pole.

A20 User Manual

14

3.7 Controller Connecting

Two ways are supported connecting between controller and A20, bluetooth and RS232.

3.7.1 Bluetooth

1. Connecting work should be done first before start FOIF survey_GPS. Using controller

scan the bluetooth signal of A20.When bluetooth is found, the SN of A20 is shown in

controller, then select this SN to finish the connecting work.

2. Set port (No. of port can be searched from bluetooth settings in controller.) and baud rate

of controller to finish connecting.(More shown in FOIF_survey User Manual)

3.7.2 RS232

Using serial port cable to build the connection by setting the port with COM1 and baud rate

with 19200.

3.7.3 State of Connecting Shown

When connection is successful whether by bluetooth or RS232, you can comfirm from the

screen of A20. or would be displayed on the screen, means RS232 while

means bluetooth.

3.7.4 Disconnecting

Menus in FOIF Survey_GPS software, Configuration Com configuration, you can stop

the connecting work by selecting the other COM port. While doing so, A20 receiver is still

working normally, but you can not control the receiver by using your controller.

A20 User Manual

15

4 General Introduction

4.1 Nomenclature

Frontal panel

upper cover

inner antenna

shockproof rubber ring
(anticorrosion)

port for the antenna
of inner radio

displayed/operating
interface

lower cover

battery/SIM card/
slot for SD card

A20 User Manual

16

Bottom of
panel

fixed system
of phase center

slot for
SIM card

speaker

communication
module

SD card

Lithium-Ion battery
(4400mAh)

place for battery

COM1(handheld connecting)
/DC IN

COM2(external radio)
/DC IN

port for the antenna
of inner radio

A20 User Manual

17

A20 User Manual

OLED Screen

4.2 Displayed Panel and Keyboard

18

BAT SAT

LINK

REC

OLED

Up
Down

ENT

ESCHot Button

PWR

Two ways are supported in battery supplied: inner Li-Ion battery or external storage battery.

While using the inner Li-Ion battery mode, capacity of battery would be displayed on the

screen by real-time detection. Charging time for Li-Ion battery should normally be less

A20 User Manual

Working time for A20 is more than 10 hours due to its high capacity chargable Li-Ion battery.

(but actual using time mayhave certain difference because of different environments)

A20 can be supported by external storage, the cable for connecting A20 and PC is standard

in A20 equipment list.

4.3 Battery

4.3.1 Ways of Battery Supplied

4.3.2 Supplied by Inner Li-Ion Battery

4.3.3 Supplied by External Storage

than 6 hours.

19

5 Receiver Operation

5.1 Buttons

5.1.1

Power (red)

Function:

1 Turn on/off

Turn on

1)Confirm that A20 is at shutdown state.

2)Press ,then loosen it.

3)Start screen would be displayed on the screen of A20.

4)You can hear the voice while turning on A20.

5)Light(BATT) is on and light(GPS) is blinking.

6)Finish.

A20 User Manual

Turn off

1)Comfirm that A20 is at working state.

2)Press for about 3 seconds unless you hear the voice while the information lossen

the power button, the receiver will be closed ,then lossen button.

3)The screen and lights on it would all be closed.

4)Finish.

20

5.1.2

Hot button

Function: 1 Start base station(including coordinate setting) according to last base station

settings.

2 Gain current coordinate instead of last coordinate of base station to set it

according to last link settings.

3 Start rover station according to last rover station setting.

4 Static state.(REC light is blinking instead of LINK light.)

Start:

1)Comfirm that A20 is not at the static state.

2)Comfirm that at least 4 satellites are tracked.(That is to say the GPS light is blinking

green continuously at least 4 times.

3)Press , then choose the item that you want to set by , then press .

4)Wait for a moment, you will see the blue light is blinking, indicating that data link

A20 User Manual

is successful (send or receiver), start surveying.

the item (base or rover) to achieve the result of your operating by the next time turning on

Notice:

If A20 is restored to factory setting, then you should turn off receiver after you have started

the receiver.

21

OKOK

5.1.3

Esc

Function:

1)Cancle without setting.

2)Return to the previous menu.

5.1.4

Enter

Function:

1)Comfirm the settings.

2)Go to the next menu.

5.1.5

Up and down.

1)Up or forward.

2)Down or backward.

A20 User Manual

Notice:

In order to avoid misoperating, you should press the button for about 1 second to achieve

your choice. If the item you want to choose is not the next item (e.g. 3 or 4 items after the

cursor

s current position), then you can press without stop until the cursor switch to the

item you want.

22

OKOK

EscEsc

A20 User Manual

5.2 LED Indicating Lights

5.2.1

Battery (green)

Function: Power Indicator.

1)>60%, green light is on without blinking.

2)40% ~60%, flash one time for every second.

3)20% ~40%, flash two times for every second.

4)10% ~20%, flash four times for every second.

5.2.2

Satellite (green or red)

Function: Display the number of satellites tracked by A20.

1)While blinking in red, indicating that A20 is searching the signals of satellites.

2)While blinking in both red and green, the times that the light blinks in green shows the

number of satellites tracked by A20.

5)<10%, A20 speaks to you.

5.2.3

Link (green)

Function: Differential Signal Indicator.

1)OFF: no signals transferring.

2)Blink regularly: normally sending or receiving signals.

3)Blink unregularly: unreliable in difference link.

23

5.2.4

Record (green)

Function: Static working mode.

1)OFF: no static surveying.

2)Blinking regularly: Static surveying, the speed of blinking is the setting interval

5.3 Displayed Menu

5.3.1 Start Screen

A20 User Manual

recording.

24

5.3.2 Main Interface

number of satellites

state of A20

COM/bluetooth

battery indicator

current accuracy

SIM card Info

indicates that SIM card is not in the receiver. If SIM card is put into the receiver,

would be displayed instead of . If receiver is connected to the controller by

bluetooth, would be displayed instead of which is the COM port symbol.

A20 User Manual

25

5.3.3 Menus in A20

Select Info. at the main interface, you will see the options like GNSS,

Radio, GPRS, Mem, Bat. and about.

Select GNSS, you will see the followed 3 interfaces. Switch them

Coordinate

Quality of satellites

by up or down arrow.

signals

Number of satellites tracked

A20 User Manual

Operating
Menu (1)

Info menu

Info/GNSS/P1

Info/GNSS/P2

Info/GNSS/P3

26

Select Radio, you will see the model and channel of radio.

Select GPRS, you will see the model and signal of GPRS.

Select Mem, you will see the Info. of memory.

Select Bat. , you will see the Info. of battery.

A20 User Manual

Operating
Menu (2)

Info/Radio

Info/GPRS

Info/Mem

Info/Bat.

27

Select About, you will see the Info. of A20 such as PN, SN, edition

of software and hardware.

At the main interface, if you choose Set, you will see the setting

options for A20 such as GPS, Link, Memory and System.

Choose GPS, you will see four options for your setting such as Mask,
Base, Rover, Static.

Select Mask, here you can set the mask of A20.

A20 User Manual

Operating
Menu (3)

Info/About

Set menu

Set/GPS (same function as hot button )

Set/GPS/Mask

28

If you choose base, then you have many options for your base setting

such as Format, Linker and Position.

In the Format column, you can choose the most suitable format for

your surveying.

In the Linker column, you can choose the module of different linkers.

In the Pos. column, you can choose the coordinate of base position.

If the base has not moved, you can choose Last for the position of

base. Instead, you can choose Current for the position of base. But

be sure to do the coordinate converting because the accuracy of base

in current mode is 10m by AUTO state.

A20 User Manual

Operating
Menu (4)

Set/GPS/Base

Set/GPS/Base/Format

Set/GPS/Base/Linker

Set/GPS/Base/Pos

29

Choose Rover for your rover setting.

At the rover setting menu, you can select the format e.g. CMR etc.

If you choose Static, then 2 options for your setting such as Store

position and Interval. Two ways are available for your menory,

NAND flash and SD card.

If you choose link, then you would have two ways for your data

transferring.(GPRS and Radio)

A20 User Manual

Operating
Menu (5)

Set/GPS/Rover

Set/GPS/Rover/Format

Set/GPS/Static

Set/Link

30

You can either Open or Close the GPRS linking.

This is the Radio(inner radio) setting interface.

Select Set, you would see the Setting Radio procedure.

You can also choose Memory to set it for storage medium.

(Flash or SD card)

A20 User Manual

Operating
Menu (6)

Set/Link/GPRS

Set/Link/Radio

Set/Link/Radio/Set

Set/Memory

31

You can Check or Format NAND Flash.

If you choose SD card as memory, then you would be mentioned to
copy Flash

s data to SD card.

This is the copying procedure.

In the System menu, you have 4 options to set.

Bluetooth, Voice, Language and Screen.

A20 User Manual

Operating
Menu (7)

Set/Memory/Flash

Set/Memory/SD card

Set/Memory/SD card/Copy

Set/System

32

This is the Bluetooth Resetting procedure.

Here you can Open or Close the Voice.

Two options are available for language.

Screen to set Contrast and OLED.

A20 User Manual

Operating
Menu (8)

Set/System/Bluetooth

Set/System/Voice

Set/System/Language

Set/System/Screen

33

A20 User Manual

Choose Add or Sub to set the contrast of the screen.

This is power saving mode by choosing OLED, then you would be

asked whether auto off OLED or not. If you choose Yes, the screen

would be Off automatically after 1 minute without affecting your

Operating
Menu (9)

Set/System/Screen/Contrast

Set/System/Screen/OLED

surveying job.

34

6 Static Surveying

A20 also has static surveying function, which includes outdoors surveying and office

6.1 Process

1) Fix A20 on tripod.

2) Measure the height of A20.

3) Turn on A20 while more than 4 satellites are tracked by this instrument, then start the

static surveying from the buttons of A20 screen.

4) It is important to record the surveying time, SN of A20,height of A20, etc. on a notebook

5) When outdoors surveying is over, turn off A20.

Notice:

Normally, it is better to record the static data on SD card.

6.2 Data Downloading and Format Converting

1) Connecting A20 and PC for data downloading.

2) File name given should according to the notes of outdoors surveying made by yourself.

SN of A20, surveying time and point name should all be indicated in the file name for

your easy distinction. For example, A20, the detailed information is,A200000086(SN

A20 User Manual

35

while this receiver is doing the static surveying.

working.

surveying at 11am to 12am on CPI0027. So then we can give its name as 0027086B which

is different from 0023086A,although we use the same receiver to do the job.(The front 4

3) Convert these data to RINEX format and input the height of A20. You can finish this by

the software FOIFGNSS shown below.

numbers are point name, the later numbers are SN of receiver, the last capital letter is

can give its name as 0023086A. Further more, still this receiver for the second time

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of receiver) for the first time surveying at 9am to 10am on CPI0023(point name), so we

surveying time.)

4) Click Import raw files for translated to RINEX , choose the files that need to be

converted.(These files are downloaded from receivers.) This software can convert as

much as 16 files at the same time.

5) Choose the files that you want to convert, then click Open . The converted files are

saved at the same path as your original files on your PC.

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7) When you have seen the window information RINEX Translation finished , then

press OK , you can see the network and baselines for your static surveying.

Detailed pictures are shown below,

8) Using FOIF post processing software FGO Geomatic Office 2008 to do the office

Detailed ways are shown in the user manual of FOIF Geomatics office 2008 .

work.

6.3 Ways of Outdoors Working for Static Surveying

1) Surveyors should give a general understanding about their surveying district e.g. point

position, difficulties of making point and also includes the economic level, culture

custom, traffic situation etc. at that place.

2) Ephemeris forecast: Good surveying opportunities should depend on the surveying

position and the latest satellite ephemeris. The satellite ephemeris includes many aspects

e.g. visibility of satellites, satellite constellation, PDOP etc. If big building is beside the

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point, then you should give a conclude on whether this big object would influence the

effects of static surveyings on that point.

3) Give a detailed surveying precedure on the paper.

4) Outdoors surveying: Comply with the surveying procedure and related receiver manual

to lead your job.

5) Data transferring: Check the consistency between outdoors notes making and the files in

the receiver by PC.

6) Process baselines to determine the accuracy of your surveying thus leading your next

working plan.

7) Finish working if there has no problem in step 6) and then print your adjusted results

report.

6.4 GPS Network

6.4.1 Network Designing

1) The baselines should be closed. Single baseline is not accepted in the designing.

2) It is not right to say that the more the baselines, the better the results are. Three baselines

for one point is suitable for the reliability of network.

3) For getting the higher accuracy of the point, one point for two times surveying is suggested.

4) In order to convert GPS system to your local coordinate system, you should have at least

3 to 5 higher accuracy known point that are equally spread in the survey district for your

good coordinate converting. At the same time, if you want to get your good elevation of

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the surveying points, then you should have certain leveling points for your research on

the elevation of your surveying district.

5) Considering the convenience of static surveying, it is suggested for you to give your

points in the wild place where you are easy-going.

6.4.2 Accuracy Standard in Static Surveying

Accuracy standard in static surveying is judged by the rms of distance in the adjacent

two points.

22

)*( dba +

: rms (mm)

a

b

d

: fixed error (mm)

: scale factor (ppm) : distance (km)

The surveying accuracy for GPS is divided into 6 levels by Surveying Standard for GPS

published in 2001 (AA, A, B, C, D, E). AA, A, B are for country

s GPS control surveying.

Level C is mainly in engineering surveying of big or middle cities. D and E are for control

surveying in middle or small cities

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Minimum distance for

Maximum distance for

Average distance for

Items

AA

A

B

C

D

E

Fixed error:a (mm)

Scale factor: b(ppm)

adjacent two points (km)

adjacent two points(km)

adjacent two points(km)

~ ~~

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6.4.3 GPS Network

There are many kinds of GPS network designing such as tracking, alternately observation,

Tracking: Several receivers fixing at the certain points for a long time observation (such

as 1 year without stop), which is suitable for level AA control survey or perma-

Alternately observation: Several receivers fixing at the points of certain district, they also

need long time surveying (several days), after this procedure, change the receivers

to the other points of this district, then use the same surveying way. This mean can

eliminate the influence of SA. It is suitable for the GPS network survey of level A

Multi-base: While several receivers are fixing at the base points (like CORS) with long time

surveying, then we can use other rovers working in this net simultaneously. It is

suitable for level C and D survey.

Single-base: Use one receiver fixing at the base point working continuously, then use rovers

to do the surveying job around base point. These rovers do not need synchron.

As a rover fix at one point, one baseline is formed. Several rovers then can form

many baselines which have the same base point like a star. It is suitable for level

D and E survey.

Normal: This way is just the general way for customers. You just follow the manual and do not

multi-base, single-base, normal.

nent monitoring survey.

and B survey.

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simultaneously. This moment, one polygon is formed by these receivers. After the first

surveying time is over, move these receivers to other points doing the same surveying job

(another polygon is formed by the second time surveying) but make sure that the two

polygons should have common side. The whole GPS network is formed by these polygons.

6.4.4 Shapes of GPS Network

Depend on different applications, shapes of GPS network can be divided into several types:

Radial network, Point connecting network, Side connecting network, Polygon connecting

network and Mixed connecting network.

Radial network

Radial network is a simple geomatic figure, but it is not

easy to check the accuracy because all the sides of that

network are not closed. The advantages for this type is:

only need 2 receivers, which is regarded as an easy-working,

fast-tracking way. It is widely used in low precision

engineering surveying, cadastra survey, mapping and so on.

fixing on points to do the static surveying for a certain while (usually 40-60 minutes)

need to have many professional knowledge. Detailed way is, using 3 or more receivers

It is suitable for level C and D survey.

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Point connecting network

Point connecting network is defined as a figure by connect-

ing two adjacent shapes by only one common point. The

advantages for this type is high efficiency, fast extending,

but it also can not confirm the high precision surveying. So

it is not suggested in precise working.

Side connecting network

Side connecting network is defined as a figure by connect

ing two adjacent shapes by their common side. It is as same

as normal GPS network designing shown in the last para-

graph and is widely used in the surveying field because of

On the left is 3 receivers working simultaneously in the

Point connecting network.

its high precision.

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Polygon connecting network

Polygon connecting network is defined as a figure connect-

ing the two adjacent shapes by at least 3 common points.

So this network at least needs 4 receivers. It is better than side

connecting network in accuracy but not working time. So it is

only suggested for high precision control surveying.

Mixed connecting network

Because every type of network has its own disadvantage, so we can use Mixed connecting

network which can combine the advantages of these types to achieve higher efficiency

working but lower investment both in time and money.

Mixed connecting network is also the common type in doing the surveying job.

6.4.5 Principles of GPS Network Designing

Principles for GPS network designing include 3 parts, point position, reliability and

accuracy.

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Point position

1)Widely place is suggested because of good satellites signals, big buildings are not

allowed at the range of 10~ 15

in elevation mask.

2)Keep 200m away from high power WiFi object, e.g. radio, powerline etc.

3)It is better to be removed from the large water area, high building etc. to avoid or reduce

the effects of multipath.

4)The place for point position should be easy-going and also steady for further applications.

Reliability

1)Longer surveying time.

2)Repeated station setting is suggested.

3)Comfirm that one point should be involved at least 3 baselines.

4)The sides for every part of the network should not exceed 6.

Precision

1)Synchronous surveying is suggested in the adjacent points.

2)GPS network designing is suggested.

3)The sides for every part of network should not exceed 6.

4)High precision EDM instrument is recommended to use together with GPS receivers.

5)Leveling points should be equally spread in the district for better elevation fitting.

6)Surveying time (times) could be added appropriately for higher precision surveying.

7)Known points should be equally spread in the district for better precision surveying.

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7 Specifications

7.1 Physical Specifications

Feature

Specification

Size 228*204*95mm

Weight:with battery

1.7kg

Operating time

Operating temperature

Storage temperature

Humidity

Water/Dust proof

Drops

>10 hours

-30 to +65

-40 to +75

Up to 100%

IP67,IEC529

2M pole drop

7.2 Positioning Specifications

D:distance Km

Feature

Specification

Postprocessing

Horizontal

Vertical

Real-time(RMS)

Horizontal

V ertical

2.5mm+1ppm*D

5mm+1ppm*D

10mm+1ppm*D

20mm+1ppm*D

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7.3 Technical Specifications

Feature

Specification

Tracking

Communication

Data formats

GPRS

Internal memory

Radio

RS232,Bluetooth

RTCM, CMR, CMR+, NMEA-0183

128MB

UHF 390MHz ~ 470MHz

54 channels, GPS 14L1,14L2,

GLONASS 12L1,12L2,2SBAS

Support GPRS

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7.4 Technical Specifications for Controller

7.4.1 Getac PS236

Feature

Specification

CPU

Operation system

Communication

Working distance

I/O

Dimensions

Weight

Operating temp

Storage temp

Humidity

Water/Dust

Drops

Memory

Display

PXA310 806MHz, 32bit RISC CPU

3.5 in.VGA full colour touch screen, llumination

Microsoft Windows Mobile 6.1

128MB, extend SD card

Integrated bluetooth and RS232

10m (for bluetooth)

USB/RS232

178*89*30mm

0.5kg (Include battery)

-40 ~+70

95%

IP65, IEC529

1.52m (5ft) drops to polished concrete

-30 ~+60

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7.4.2 Getac PS535E (optional)

Feature

Specification

CPU

Operation system

Communication

Working distance

I/O

Dimensions

Weight

Operating temp

Storage temp

Humidity

Water/Dust

Drops

Memory

Display

Samsung2440 400MHz,CPU

3.5 in.VGA full colour touch screen, llumination

Microsoft Windows Mobile 5

2GB, extend SD card

Integrated bluetooth and USB

10m (for bluetooth)

USB

144.25*82.25*29.3mm

0.3kg (Include battery)

-30 ~+70

95%

IP54

1.52m (5ft) drops to polished concrete

-20 ~+60

SUZHOU FOIF CO., LTD.

ADD 18 Tong Yuan Road, Suzhou 215006, P.R. China

TEL: [phone]

FAX: [phone]

Http://www.foif.com.cn

E-mail: [email protected]