Relative clock estimation method between two LEO satellites with a double-difference solution constraint

A method of estimating the relative clocks between two spaceborne global positioning.system (GPS) receivers based on the single-difference (SD) observations is investigated in.this paper. Especially, the advantages of introducing a double-difference (DD) solution.constraint, including the orbits and ambiguities, are discussed with the simulated data.and the real data of Gravity Recovery And Climate Experiment (GRACE) satellites. The.theoretical accuracy analysis shows that the accuracy of the re