A new method for ARM detection based on Adaptive Linear Prediction Error Filter (ALPEF) is proposed in this paper.The method is proved to be fast
reliable for detecting ARM signal in a very low aircraft to ARM signal ratio.Its mechanism is based on the elimination the strong aircraft signal from the radar echoes.Computer simulation results show that a very good detection performance is achieved in a -20dB aircraft to ARM signal ratio
so that a reliable early warning of ARM launching can be given.