What do the numbers next to DOP on the satellite page mean?
On models GPS-100 and GPS-200 it means Dilution of Precision(DOP): an indicator of satellite geometry for a unique constellation of satellites used to determine a position. Positions tagged with a higher DOP value generally constitute poorer measurement results than those tagged with lower DOP. The ideal orientation of four or more satellites is to have one satellite directly overhead and the other three evenly spaced around the receiver. In the diagram at the right, all the satellites are clustered together in one quadrant of the sky. This would result in a poor DOP value. A low DOP value represents a good satellite configuration, whereas a higher value represents a poor satellite configuration. The DOP changes with time as the satellites move along their orbits.
