Working with GNSS

The GNSS Status icon (e.g. , top left of the screen) shows you the status of the GNSS positions being received and their estimated accuracy.

High accuracy GNSS is required to accurately place a model in your surroundings using the measured and automatic placement functions.

NOTE – Your mobile device must be connected to an Internet source with a 3G connection as a minimum, to receive corrections for high accuracy GNSS positioning. Without an Internet connection, GNSS positioning will not be as accurate; Trimble Correction Hub connects you to the satellite-delivered RTX correction stream or to a local SBAS service.

The GNSS Status icon will show any of the following:

  • Red with no numbers. The system is starting for the first time, or is not running.
  • Red with numbers. The system has started tracking satellites. If the distance number is displayed the system is using the satellites to generate a position.
  • Yellow with numbers. The system is receiving differential corrections from a source and the position accuracy lies between 0.5 m (1.64 ft) and 5 cm (0.16 ft)—or the minimum accuracy you have set for GNSS.
  • Green with numbers. The GNSS positioning accuracy has reached the threshold set for the accuracy limit (default 5 cm / 2 inches) to permit viewing and positioning models.

The information shown on the GNSS Status icon is as follows:

  • number in the top right = number of satellites being tracked during start up or being used in the positioning solution.
  • distance value at the bottom = estimated accuracy of the GNSS position.

The default minimum GNSS value is 5 cm (0.16ft). When the estimated accuracy is at this value or less, the GNSS Status icon turns green.

To change the minimum value tap / Tools/ Configuration, then tap Advanced and set the GNSS Minimum High Accuracy.

When using the Trimble RTX correction service, Trimble recommends that you change this threshold to 20 - 30 cm (0.66 -1 ft), provided that this level of accuracy is sufficient for the type of work the model is being used for.

NOTE – If you change this setting it is applied to all future work. If you are going to use the system later for tasks requiring greater accuracy, you must change the value back to a suitable level for the future work.

 

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