For GPSAPP the display area between the satellite signal strength bar graphs and the polar plot of satellite elevations and azimuths has the following information:

The first line shows the altitude in feet or meters and is dim when the position data is derived from a 2 dimensional solution (2D) and bright when the receiver provides a 3 dimensional solution (3D). Your receiver will typically use 3 satellites and the last known altitude or a user entered altitude if it is set to 2D or has only 3 satellite signals available.

The second line shows your GPS measured velocity if it is available from the GPS receiver.

The third line shows the HDOP (Horizontal Dilution Of Precision) as provided by the receiver. This is a guide to the degradation in horizontal position accuracy that can be attributed to the geometric relationship of the satellites (being used for the solution) to the user's receiver.

The fourth line shows whether the GPS receiver is operating in 2D mode or a 3D mode. and also the number of satellites being used to compute the solution. This number can be more than 4 if the receiver is able to compute an "overdetermind" solution.

Lynn