The invention discloses a GPS /
GLONASS inter-frequency
clock deviation modeling and forecasting method and device, and the method comprises the steps: obtaining positioning data received by a
receiver from a
satellite, and constructing a geometric-free
ionosphere-free phase combination observation value according to the positioning data; an inter-epoch difference method is adopted to remove
ambiguity constants absorbing phase hardware
delay time invariants in the geometry-free
ionosphere-free phase combinations, and a single observation
station ionosphere-free combination IFCB is obtained; integrating
observation data of multiple observation stations, and calculating a final IFCB deviation by adopting a multi-
station weighted average mode; according to the IFCB data, carrying out
harmonic analysis by adopting
fast Fourier transform to obtain an accurate period of an IFCB sequence, and proposing an IFCB model based on a third-order polynomial and a seven-period
harmonic function; and performing experiment forecasting according to the IFCB
time sequence model, extracting and comparing periodic characteristics of IFCB deviation, and calculating an optimal forecasting period. According to the method, the
observation data of the GPS /
GLONASS system can be corrected in real time, so that the positioning result is accurately corrected to improve the positioning accuracy.