Noncooperative Bistatic Radar Countermeasures Based on the Joint Design of Radar Waveforms and Mismatched Filters

Noncooperative bistatic radars (NCBRs) do not transmit electromagnetic waves but use emitters of other host radars as illuminators for target detection. If the noncooperative bistatic radar and the host radar belong to the opposing camps, respectively, the noncooperative bistatic radar will be a great challenge to the host radar. To ensure the electromagnetic information security of host radars, a joint design of host radar waveforms and mismatched filters (MMFs) is proposed to reduce the detection performance of NCBRs. For NCBRs, we raise the autocorrelation function sidelobe levels of the transmitted waveform to deteriorate its detection performance. For host radars, we design an MMF to improve the target detection performance of such transmitted waveforms. The simulation results show that the effects of raising and suppressing the range sidelobes in the model are both achieved. The price is an additional SNR loss (about 2 dB). Two types of transmission waveforms are designed including mainlobe broadening (MLB) waveforms and false peaks (FPs) waveforms, by controlling the autocorrelation function elevated position parameter. The constant false alarm detection results show that the designed waveforms fulfill the requirements of noncooperative bistatic radar countermeasures.

I. Introduction

Noncooperative bistatic radars (NCBRs) do not emit electromagnetic waves, but use other transmitters as illuminators [1]. Illuminators of the NCBR include FM radio broadcast, TV broadcast, GSM, navigation satellites, Wifi signals, and radar emitters [2], [3]. In addition to the famous “Silent Sentry,” there are some noncooperative bistatic radar experiments that are specific to radars. As early as 2005, the German Matthes [4] team used the Ka-band low-intercept probability FM continuous-wave radar as a host radar to achieve moving target detection. Ito et al. [5] of Japan’s Mitsubishi Corporation carried out a moving target detection test of the NCBR using a mechanical scanning airport surveillance radar as a host radar.