To detect and track a target at a long range, and at short range to improve the guidance properties to the target, a clutter resistance and response properties to a circling target with higher distance resolution, by switching from a doppler tracking means (FFT processing) to a range tracking means (composite bandpass processing) or vice versa, according to the conditions of tracking of the target.

A guidance system is provided with a local oscillator which outputs a local signal and a signal having a transmission frequency, based on an inner state set; a transmitter which amplifies the signal having the transmission frequency and outputs a transmission signal; a transmission / reception switch which switches the transmission signal and a reception signal; an antenna which transmits the transmission signal into a space and receives a reflection signal from the target; a receiver which converts the frequency of the reflection signal from the target, by using the local signal output from the local oscillator and amplifies it to output a video signal; an A/D converter which converts the video signal into a digital signal, an FFT processor which subjects the digital signal to a frequency process; a target detector which detects the target to be tracked based on a result of the frequency process; and an angle detector which detects angle information in relation to the target to be tracked. The guidance system further includes a guidance signal calculator, a composite bandpass processor, a target detector, and a mode-switching section.