Terrastar-C is a a GNSS correction service that can be utilised to improve the accuracy of your unit.
Requirements to use Terrastar-C
- V2 RT, Survey+ or OEM products can support Terrastar-C
- xNAV, Inertial+, RT2500, and RT3100 devices cannot support Terrastar-C
- Compatible GNSS firmware
- PPP requires firmware version 6.600 or above for Terrastar-C
- If you don’t have the latest firmware, contact OxTS support
- a Terrastar-C subscription from your local NovAtel dealer. You can order one through your respective country/region http://www.novatel.com/where-to-buy/dealers/
- Antennas that support L-Band frequencies. All antennas that are supplied with compatible OxTS devices are suitable. Should you have any doubts, contact OxTS support.
- GLONASS is recommended, as it will enhance the performance.
Setting up Terrastar-C
To set up Terrastar-C, follow the steps given below:
- Power up OxTS device and connect it to your computer.
- Open NAVconfig:
- Select OxTS product;
- Device orientation settings;
- Antenna settings: primary, or secondary if needed;
iii. Wheel/Advanced Slip settings.
Performance options in NAVconfig
Once this point of the configuration has been reached, the DGNSS service option needs to be enabled. This is the key stage of the Terrastar-C setup.
The DGNSS service option, shown in Figure 1, has three options to select from the drop-down menu:
- Automatic: Should be the default choice, unless a specific satellite needs to be tracked.
- Manual: If a specific satellite needs to be tracked, simply select manual from the drop-down menu and then click on relevant satellite as shown in Figure 1.
Further required options
Please note that OxTS gx/ix™ algorithms cannot currently use Terrastar-C corrections, so you should ensure that the GNSS control option is set to Default for RT and Other for Survey+ family products.
The final step is to configure the OxTS device to log Terrastar-C status messages, which are needed for troubleshooting or verification of service purposes. To do this, enter the following commands into the Advanced options section, as shown in Figure 2.
- ->gps1: LOG TERRASTARSTATUSB
- ->gps1: LOG TERRASTARINFOB ONCHANGED
- ->gps1: LOG LBANDTRACKSTATB ONTIME 1
- Commit configuration to device and save configuration.
Following the configuration, open NAVdisplay and use the relevant warm-up PPP template to view the GPS position mode. Figures 3 and 4 show NAVdisplay for a RT2002 device before and after initialisation, respectively. In Figure 5, mode 31 appears once PPP has converged.
NOTE: If you have just bought a Terrastar-C subscription, ensure that the unit is left on to receive the signal, this may take some time, so you may need to leave the unit on overnight. If you think that you've missed the activation signal, Terrastar mention "The system will rebroadcast the activation signal at 2-3 hour intervals."
If you cannot see PPP mode within NAVdisplay after following this guide, then contact OxTS support