Catalyst GNSS Behavior
Frequently Asked Questions
What GNSS satellite technologies does Catalyst support?
Technical details of the GNSS capabilities of Trimble Catalyst are documented in the Trimble Catalyst system datasheet. Catalyst can use GNSS data from any signals tracked by the Trimble DA1 antenna. Currently the DA1 can track GPS L1/L2C, Galileo E1, GLONASS, SBAS, and RTX L-band. Use of satellites in the GNSS solution depends on the capabilities of your GNSS correction source, as well as your active Catalyst subscription type.
What GNSS correction sources can Catalyst use?
Out of the box, Catalyst uses the Trimble Corrections Hub (TCH), a new bundled correction source concept that eliminates the need for any user configuration or intervention. Trimble Corrections Hub provides access to Trimble VRS Now (where available), Trimble RTX via IP (available globally) or L-band (where available), and SBAS. TCH uses your location and subscription to determine which of these services to use, and will automatically fall-back to an alternative source if the first or second choice is unavailable. Access to each of Trimble's VRS Now and RTX IP and RTX L-band correction services is enabled automatically by the Catalyst subscription. For users of Catalyst Precision and Decimeter services in regions that fall outside of Trimble's current Catalyst-ready VRS Now service areas, a local correction source can be configured as an alternative to using Trimble Corrections Hub. Users of local correction sources may be required to pay an additional access charge for this service. Check with your local correction source provider for more details.
What GNSS correction formats does Catalyst support for local correction sources?
Local corrections need to be broadcast in RTCM 3.0, 3.1, 3.2, or Trimble's proprietary CMRx format. For best results, use RTCM 3.2 or CMRx format corrections, if available. CMR and CMR+ format are not supported.
In what format are Catalyst GNSS positions output?
Trimble Catalyst outputs the following position values:
- Latitude (decimal degrees)
- Longitude (decimal degrees)
- Altitude (height above ellipsoid - meters or feet)
Trimble Catalyst does not support Altitude values referenced to a local or global Geoid model. If your workflow requires positions relative to Mean Sea Level (MSL), these need to be computed inside your workflow application using values for Height Above Ellipsoid (HAE) generated by the Catalyst engine.
How do I get my app to use Catalyst positions?
Catalyst positions can be accessed in one of three ways, the appropriate method will depend on the capabilities and the level of integration of the application you want to use:
Catalyst-embedded applications - Some applications (e.g. Trimble TerraFlex or Trimble PenMap for Android), embed controls for connecting to Catalyst directly inside the app. All you need to use these apps is the most uptodate version of your app, and the Catalyst Service. Configure the app to use Catalyst as the GNSS source, and Catalyst will be used as the solution's GNSS receiver.
Catalyst-ready applications - Applications developed using the Catalyst SDK can communicate with Catalyst programmatically, but still use the Trimble Mobile Manager to configure the receiver, and to sign-in to access the Catalyst subscription. For these apps you require the current version of your workflow app, Trimble Mobile Manager, and the Trimble Catalyst service installed on your device. Configure your workflow app to use or connect to Trimble Catalyst, and manage the connection to the receiver through the Trimble Mobile Manager app.
Third-party location aware applications - Most apps just want to receive a GNSS position from the on-board GPS receiver of the phone, and communicate to the device using Android's Location Services. To over-ride your phones internal GPS with the higher accuracy positions of Trimble Catalyst, you need to enable Mock Locations, and to set Trimble Catalyst as the Mock Location provider for your device. Refer to the user documentation for your phone for instructions on how to do this. To use Trimble Catalyst in this way, you need the Trimble Mobile Manager app and the Trimble Catalyst Service installed on your phone.
What location information is available when using Catalyst with Android Mock Locations?
To enhance the functionality available to third party location enabled applications, Trimble Mobile Manager adds an additional set of metadata information to each position, which extends what is generally available through the standard Android Location API. This additional metadata is typically referred to as Location Extras.
A detailed overview of the available Location Extras as added by Trimble Mobile Manager can be found in the Trimble Precision SDK for Catalyst Developer Guidelines or Trimble Mobile Manager for Developers guideline documents. Both documents are available to download in the Trimble Catalyst Online Developer Community.
What reference frame are Catalyst positions output in?
Catalyst can output positions in either a local or a global reference frame.
If you are using a Catalyst-embedded application, refer to the documentation of your application for details of any custom GNSS functionality that have been implemented.
If your app uses Trimble Mobile Manager to configure Catalyst, you can customize the output reference frame of positions to suit your existing data or the background map that you are using the Target reference frame setting.
For details on how to use this setting, refer to the Trimble Mobile Manager User Guide.
For recommended settings for different workflows, refer to reference frame topics in the Trimble Catalyst User Community.
Can I log raw measurements or postprocess my Trimble Catalyst data?
Raw data logging and postprocessing workflows for Trimble Catalyst are not currently supported.