Please note that Ground Truth won't be available when Global Mode is active.

The Ground Truth or GT is the real location where you are at a certain moment. Situm Mapping Tool allows you to indicate where you are while positioning: this information will be captured as ground truth and sent to our cloud alongside all the sensor data of your positioning session. This will help us troubleshoot remotelly any positioning problem you may have in your building.

In order to capture the Ground Truth, go to Display and Advanced Settings and enable the "Use ground truth" option.  

Then, go to the Positioning Screen and start the positioning. After that, you may at any time perform a long-press on the floorplan (to indicate your real location). As shown in the following figure, a green circle marker will appear at that spot: this location will be recorded as your real location at that precise moment. You may keep walking and repeat this process as many times as you like: the more data we have, the better we can assist you.