MULTIPATH DETECTION METHOD, MULTIPATH DETECTION PROGRAM, MULTIPATH DETECTION DEVICE, AND GNSS RECEIVING DEVICE

PROBLEM TO BE SOLVED: To reliably detect multipath even if a code phase difference between a direct wave signal and a multipath wave signal is small.SOLUTION: A first replica signal having 1 chip delay and a second replica signal having 1+x chip delay with respect to a Prompt replica signal are provided to a Pe correlation part 31 of a multipath detection part 55. The Pe correlation part 31 performs correlation processing between a baseband signal, and the first and second replica signals; and performs a differential calculation for a correlation result between the baseband signal and the second replica signal from a correlation result between the baseband signal and the first replica signal. The differential calculation result is theoretically zero if it contains only a direct wave signal, and a predetermined value other than zero if it contains a multipath wave signal. Thus, a multipath determination part 32 sets a threshold value Th other than zero and compares the differential calculation result with the threshold value Th, to determine the presence or absence of multipath.