Automatic ground clutter rejection in weather pulse radar system

摘要

In a weather radar system wherein echo signals are linear- detected from the waves received at the radar, each one of echo signals being compared with the later one to derive AC component, and the mean power of the weather echo estimated from the power of the AC component, the linear- detected echo signals are amplitude suppressed before compared. The amplitude suppression effectively removes the errors due to the fluctuation of ground clutter, and the variation of AC power of weather echo due to the existence of ground clutter. An amplitude suppressor is used which has an amplitude suppressing property expressed by Y=X.sup.k, where X is an amplitude of the input signal, Y is an amplitude of the output signal, and k is a constant (0 k 1). The value of k is advantageously 0.3-0.9, and, more advantageously 0.6-0. 7. If the echo signals are obtained in a form of a logarithmic signal, an amplitude suppressor which has an input-output characteristic expressed by, for example, Y=10.sup.kZ/20 (Z: amplitude of input signal, Y: amplitude of output signal) can be used.