Valid and invalid positions in GpsGate Server
In this article we want to address the most common questions about invalid positions and how they are handled in GpsGate Server.
What are invalid positions
A position is invalid when the tracker sends non-updated or unreliable position information. In other words, if a tracker sends data when it is not possible to determine its location, it will generate a message with an invalid position.
The most common factors that make a position invalid, among others, are these:
- The GPS device isn’t located under clear sky.
- The number of satellites at the current location are not enough to triangulate a position.
- The type and location of the GPS antenna (internal or external).
How invalid positions are displayed
There are several ways to observe invalid positions:
Observing the Tracking Points
You can distinguish invalid positions because they are greyed out in comparison to the valid ones, or you can even add the column Valid to the list.
Analyzing the Terminal Window data
Another approach to verify if a position is invalid or not, is by inspecting in the Terminal.
- Invalid positions are not being taken into account when the tracks are drawn on the map. Only valid positions are represented as tracks when using Draw tracks option in the Tracking Points panel.
- Read more about diagnosing terminal data here.
Invalid positions and Event Rules
Invalid positions are not being ignored by Event Rules. Regardless of whether the position is valid or not, a new message may contain additional useful information (eg. a new temperature value from the thermometer connected to an input in the device). Event Rules will process this message if it complies with the proper sending method.
Invalid positions and Reporting
Invalid positions are considered in reports in general, however, information in reports that requires a valid position to be correct will handle with the invalid positions suitable for that given function.
(e.g: If distance is calculated using GPS positions, the invalid position will not be part of that calculation).
- Note: Addresses will not be looked up if the position for the address is invalid.