Pseudorange

Pseudorange is the measured distance between a GNSS satellite and a receiver, determined from the travel time of a coded signal multiplied by the speed of light. It is termed “pseudo” because it includes not only the true geometric range but also receiver and satellite clock offsets, atmospheric delays, and other error sources.

In geodesy, pseudorange observations are fundamental for determining receiver position and time, particularly in real-time and navigation applications. Although less precise than carrier phase measurements, pseudoranges are essential for ambiguity resolution, initial positioning, and clock synchronization in GNSS data processing. They form part of the observation equations used in precise positioning and reference frame realization.