Frequently Asked Questions

SiteVision and GNSS Technology

What GNSS Satellite Technologies does Trimble SiteVision support?

The Trimble SiteVision system has the ability to track the following satellite constellations: GPS, GLONASS, QZSS , and Galileo. To use these constellations the correction source needs to support these constellations. For more information about Trimble Corrections Hub go to

What type of GNSS positions can Trimble SiteVision use?

Trimble SiteVision uses Trimble Catalyst technology. The SiteVision Application displays the type of positioning solution being used under the GNSS menu. These are: Autonomous, RTK Float, RTK Fixed, Differential, RTX, SBAS, RTXCode.

The Trimble Catalyst service monitors the accuracy that your system can achieve from the different signal types and automatically selects and outputs the solution type with best available accuracy.

What reference frame are my positions output in?

When using the Trimble Corrections Hub you must select the Target Reference Frame that matches the reference frame of your model. The SiteVision system will apply a datum transformation used by the Trimble Correction Services ITRF to the datum of your model.

What is the difference between Source Reference Frame and Target Reference Frame?

A network (for example Trimble VRS Now) will be broadcasting coordinates in relation to a global reference frame such as ITRF2014. This is called a Source Reference Frame.

You might be using Trimble SiteVision with Trimble VRS Now, but want your coordinates in relation to a local reference frame which is commonly used for that region, such as NZGD2000. This is called the Target Reference Frame.

I want to use SiteVision indoors, do I need to have GNSS?

No. To use Trimble SiteVision indoors you do not need to have GNSS or be connected to the Trimble Integrated Positioning System (IPS). Please note that Trimble SiteVision is designed for outdoor use with high accuracy GNSS, via the Trimble SiteVision IPS handheld unit, and use of SiteVision indoors will not achieve the same accuracies.

Do I need a separate subscription to Trimble VRS Now to use SiteVision?

No. Your Trimble SiteVision subscription includes bundled access to Trimble VRS Now correction streams where it is available, and worldwide access to Trimble RTX technology.

However, if you are operating outside of a Trimble VRS Now coverage area, you will need a separate local VRS or IBSS delivered correction to achieve optimum results, which may incur additional costs.

Can I use Trimble SiteVision with Local correction sources and Internet Base Stations?

Yes. To use a local correction source such as a 3rd party or government Virtual Reference Station (VRS) Network or Internet Base Station (IBSS), you will need to deselect Trimble Corrections Hub and enter the required information under GNSS Configuration within the Trimble SiteVision Application.