Threshold circuit for radar video data

摘要

A threshold circuit comprises a shift memory (1) supplied with sampled and digitized radar video data; two adder circuits (2, 3) connected to the first and the last elements of the shift memory (1); and a selection circuit (5) for passing the greater of the two output signals from the adder circuits (2, 3). The output signal of the selection circuit (5) represents a first threshold value for the radar video data from the center element of the shift memory (1). The threshold circuit further comprises a noise level detector (6) connected to the selection circuit (4). The output signal of noise level detector (6) represents a second threshold value for the radar data from the center element of the shift memory (1). A comparator (10) and a gate circuit (13) are used to obtain the radar video data from the shift memory (1), when the amplitude of the video data is in excess of the greater threshold value.