Twice Cycle Slip Detection Methods for Space-Borne Dual-frequency GPS Receiver

On the basis of preliminary cycle slip detection by the W-M wide lane linear combination,a new method is introduced to make a second detection.The differences of the ionosphere-free L3 combination observables in the successive epochs can be used to work out the change of receiver clock errors when a-priori satellite orbit is known.For observables with cycle slips,their resulting values would be distinct from others in the same epochs.Exprimental results show that new cycle slips can be dug out while detected cycle slips in previous step are verified by the twice detection method.