JPS646780A - Signal processing apparatus - Google Patents

Abstract

PURPOSE:To ensure the detection of the signal from a target, when the target is detected from the video signal of a received reflected electric wave, by providing a circuit, which sets a judging level for target detection in correspondence with the dispersing amount of the video signal in the vicinity of a range, where the target is searched. CONSTITUTION:A reflected electric wave from a target, which is received with an antenna 12, is outputted to a low-frequency-component removing filter 15 as a video signal through a receiving circuit 13 and a detecting circuit 14. The filter 15 removes the low frequency component. The signal is outputted to a video-signal-dispersion detection part 16 and a level judging and comparing circuit 18. In the video signal detection part 16, the dispersing amount of the video signal in the vicinity of a target searching range is detected. In response to the dispersing amount, the judging level of target detection is set high when the dispersing amount is high, and the judging level is set low when the dispersing amount is low, in a judging level setting part 17. In this way, the judging level of the target detection at the certain range in increased or decreased in correspondence with the dispersing amount of the video signal level in the vicinity of said range.