The GPS Center Coordinates dialog shows a graphic rendering of the most recent position coordinates received from a attached MX-GPS-Box. If you are using an MX-GPS-Box at a fixed position, you will get a drift diagram. This diagram allows discovering inaccuracies of the position data calculated from the satellite positions, which are resulting from the installation position of the GPS receiver.
These coordinates are used to calculate a "center-of-gravity" coordinate, which is – statistically speaking – the most likely position of a stationary MX-GPS-Box. To facilitate checking the position, these center coordinates have been linked to Google Maps; the current center coordinates can thus be used as anchor position for the GPS Position Environment Event.
The Distance Center to Farthest Fix represents the potential inaccuracy when determining the position at the current location; this value can be used as minimum for the Distance parameter (with respect to the current reception conditions) when configuring the GPS Position Environment Event.
The diagram uses a maximum of 57,600 coordinates, which represents the last 16 hours of satellite reception without interruption.
It may make sense to use only a specific portion of the position records for calulating the center position (e.g. if the sensor has been moved recently and the older records still reflect the previous position). In such a case, you can use the two sliders beneath the diagram to set the start and end dates of the time range you would like to consider for calculating the center coordinates. Note that doing so will reduce the number of fixes.