Automated cycle-slip detection and correction for GPS triple-frequency undifferenced observables

In the process of GPS triple frequency observables,the rms of the integer ambiguity isn't fit for detecting and correcting cycle slips for the pseudo-range noise.The noise will be reduced with a simple running average filter or a process of combination for the raw observables.It is recommended that selecting observables after a running average filter or combination as a detection observable can detect and correct cycle slips for single frequency.Four principles are proposed for constructing detection observables and three geometry-free linear combinations are chosen according to these principles.Cycle slips can be detected and corrected for triple-frequency undifferenced observables with these selected detection observables.