PURPOSE: To perform continuous tracking, to stably and accurately guide a mother machine to a radio wave radiation source, and to accurately and speedily discriminate the number of times of pulse repetition by providing a receiver with a target memory and a pulse analyzer.

CONSTITUTION: The reception frequency of an antenna 1 is discriminated 11 and a tracking guidance controller 9 controls the reception frequency of the receiver 2 according to the discrimination result. The sum and difference signals from the receiver 2 are A/D-converted 4, and the amplitude, pulse arrival time, pulse width, and angle error are detected 12, 13, 14, and 7; and the data on the amplitude and pulse arrival time are stored in the target memory 16 and then utilized as information for tracking and guidance. An address generator 15 uses data for the reception frequency and angle control data indicated by the receiver 2 and an antenna servo 3 from the controller 9 and receiver 2, the angle error data from the detector 7, and the pulse width data from the detector 14 as addresses of the target memory 16. The pulse analyzer 17 performs convolutional integration for amplitude data on the time base in the memory 16 with a reference function in a tracking data memory 10 to discriminate a special received wave.