Recovery method from cycle slip in GPS positioning

GPS has been spreading rapidly for its confidence and usefulness, and now it is used in various situations. But, in the downtown, it is known that the performance of positioning deteriorates. It is because the signal from satellites is intercepted frequently by obstacle and necessary number of satellites can not be visible frequently. Particularly in positioning with carrier phase, this problem is very important because discontinuous of ambiguity occurs (cycle slip). To aim the precise positioning with the carrier phase in bad situation, we suggested new method of redefine of ambiguity.