Integer Ambiguity

Integer ambiguity is the unknown whole number of carrier wave cycles between a GNSS satellite and a receiver at the start of carrier phase observations. Because carrier phase measurements provide only the fractional phase at the time of signal reception, the total number of complete wavelengths must be estimated as an integer parameter.

In geodesy, integer ambiguity is a fundamental parameter in high-precision GNSS processing. Accurate estimation and fixing of integer ambiguities enable millimeter-level positioning, which is essential for crustal deformation monitoring, reference frame realization, precise orbit determination, and Earth system studies. The successful resolution of integer ambiguities significantly improves positioning accuracy and solution stability.