PDOP Calculator & Dilution of Precision Formula

PDOP (Position Dilution of Precision) is a measure of how satellite geometry affects GPS position accuracy. Lower PDOP values signal good geometry for positioning, while higher PDOP values indicate poor geometry and increased error magnification.

GPS Position Dilution of Precision Calculator

INPUTS:

• Qxx = 1.2
• Qyy = 1.0
• Qzz = 2.3

OUTPUTS: PDOP = 2.12

GPS PDOP Formula

Benefits/Applications

• Evaluates GPS satellite constellation quality at any epoch.
• Helps surveyors, GIS professionals, and developers assess expected positioning uncertainty.
• Combines with error budgets (UERE) to estimate position error.

Summary: The PDOP calculator guides users to understand how satellite arrangement impacts horizontal and vertical accuracy before performing real GNSS solutions.