The Initialisation of the Rover receiver is done with the GPS > Start Rover submenu or with the button shown above.
Different settings can be chosen (vary with the used receiver type):
4.4.3.
Start Rover
The Initialisation of the Rover receiver is done with the GPS > Start Rover submenu or with the button shown above.
Different settings can be chosen (vary with the used receiver type):
| Fixing Par. | This value has an effect on the reliability for the ambiguity fixing. For more information see below in this chapter. |
| Radio Port | Select the input-port for the differential corrections via radio or cell phone (GSM) modem. Chose between A, B, C, and D. Default is port C. |
| Min. Elev. | Elevation cutoff. Satellites below this elevation will not be used for position calculation. |
| Max. PDOP | Threshold value for controlling PDOP. If a measurement with a PDOP higher than this value is stored, GART-2000® CE displays a warning message. Nevertheless the measurement may be saved. |
For TPS-receiver you can choose the RTK-Mode
(extrapolation or delay), the Antenna
(internal, external or automatic), the Sat
system (GPS or GPS&GLONASS) and optionally activate the Multipath-Reduction.
The RTK-mode
can be set to ‘extrapolation’ or ‘delay’. Extrapolation
decreases the latency of the position and can extrapolate through short radio
outages. Delay
is more accurate and is the normal mode for RTK surveying of fixed points.
The
fixing parameter defines the confidence interval for the ambiguity fixing:
|
confidence interval |
fixing parameter Ashtech | fixing parameter TPS |
| no ambiguity fixing |
float |
float |
|
90 % |
very low |
-- |
|
95 % |
low |
low |
|
99 % |
medium |
medium (default) |
|
99,9 % |
high (default) |
high |
| 99,99 % | very high | -- |
A confidence interval of 99.9% means that statistically one out of thousand
ambiguity fixings is wrong.
The mode high
stands for the most reliable ambiguity fixing, but takes most time. The mode low
is the fastest, but there is a higher possibility of a wrong ambiguity fixing.
The value high is recommended for most static or kinematic applications.
The mode float means that the receiver will not try to fix the
ambiguities. This feature works only with Ashtech GG24 or with TPS receivers.
Use the <OK>-button to
initialise the Rover receiver. Be sure of having chosen the right settings in the submenu Initial
> Constants > GPS because these settings affect the Rover Initialisation.
The button <Sat> shows
the available satellites if GART-2000®
CE is able to establish a
connection to the GPS receiver.
The
satellite overview displays the satellite number, the azimuth, the elevation and
the signal/noise-ratio of the received satellites.
For TPS-receivers the GPS satellites are marked with a 'G‘, GLONASS satellites with a 'R'
in the first row.
For Ashtech receivers there is an additional flag ('-' or 'U' ). The satellites
are marked with a 'U' if differential
corrections exist for a satellite. Otherwise, a '-' is shown.
The button <Sky-Plot> shows the
actual geometry of satellites on screen.
Using the differential correction format Standard
NMEA there will be another dialog when using the menu GPS
> Start Rover:
The field Script
offers three different possibilities to initialise the Rover receiver:
- No
Script: Use this kind of Initialisation, if the Rover receiver automatically sends data and must not be
initialised with any commands.
- Manual Input: There may be entered separate commands into the field Send
to initialize the Rover receiver.
- File: Load a
scriptfile with several commands to initialize the Rover receiver. Use the
button <...> next to the field Scriptfile to select the file.
The button <Sat> shows
the available satellites if GART-2000®
CE is able to establish a
connection to the GPS receiver.
Use the <OK>-button to
initialize the Rover receiver or to send a command.