Azimuth measuring apparatus and method of calculating arrival direction of radio wave

摘要

PROBLEM TO BE SOLVED: To solve the problem in which an arrival azimuth of radio waves arriving from a covering region of an antenna cannot be measured when abnormality occurs in one part of the antenna or reception processing circuit in a latter part of the antenna.SOLUTION: A calculation method of a radio wave arrival azimuth according to the present invention has the means of: acquiring a first table indicative of a relationship between respective reception signal intensity of at least four antennas having directionality and an arrival azimuth of a radio wave; detecting abnormality of the antenna on the basis of the first table and three reception signal intensity values of the measured reception signal intensity vales; acquiring a second table indicative of a relationship between respective reception signal intensity of the at least four antennas excluding the antenna having the abnormality detected and the arrival azimuth of the radio wave when the abnormality of the antenna is detected; and calculating the arrival azimuth of the radio wave on the basis of three reception signal intensity values of the measured reception signal intensity values and the second table.