Vertical Dilution of Precision (VDOP)
Vertical Dilution of Precision (VDOP) is a measure used in satellite navigation systems, such as GPS, to quantify the impact of satellite geometry on the accuracy of vertical positioning. It indicates how well-positioned satellites are in relation to one another in the sky, with a lower VDOP value indicating better satellite geometry and, therefore, higher accuracy in determining vertical position. A high VDOP value can result in decreased accuracy in determining altitude.