User's Manual Part 2

GeoExplorer 2008 Series User Guide 69
Using the GPS receiver 5
Using SBAS corrections
The GeoExplorer 2008 series handheld has an integrated receiver that uses Satellite
Based Augmentation Systems (SBAS) correction messages to improve the accuracy
and integrity of GPS data.
The default SBAS tracking mode is Auto. In Auto mode, the receiver tracks or locks
onto the most powerful satellite signal. The GPS receiver can track two SBAS satellites
at the same time in Auto or Custom mode. It uses corrections from only one SBAS
satellite at a time, but tracking two satellites can improve the availability of SBAS
real-time corrections. For example, if you are working in environments where obstacles
may block the direct line of sight to the SBAS satellite, there is less chance of signal loss
if you are tracking more than one SBAS satellite.
Note – To turn off multiple SBAS satellite tracking, select Custom mode and then deselect
all other SBAS satellites except for the satellite you want to track.
The receiver tracks SBAS satellites according to your geographical location:
• Wide Area Augmentation System (WAAS) satellites are tracked in the
Continental United States including Alaska, and parts of Canada and Mexico.
• European Geostationary Navigation Overlay Service (EGNOS) satellites are
tracked in Europe.
• MTSAT Satellite-based Augmentation System (MSAS) satellites are tracked in
Japan.
You can configure the receiver to use particular SBAS satellites in the Integrated SBAS
Settings form of the Trimble GPS field software. Select the Custom option in the
Tracking Mode field and then enable or disable tracking for any specific satellite.
Note – If you have other Trimble GPS field software installed, configure real-time
correction settings in that application instead of the GPS Controller software.
To use SBAS corrections:
1. In the GPS field software, open the Real-time
section and tap the
Setup button .
2. In the Choice 1 field, select Integrated SBAS.
3. To select particular satellites, tap the
Setup
button next to the Choice 1 field. Select
Custom tracking mode and then enable or disable
tracking of particular satellites. Tap
OK to return
to the Real-time Settings screen.
4. In the Choice 2 field, specify whether to use
uncorrected positions, or to stop using GPS
positions, if corrections are not available.
5. Tap
OK.