A Study On Characteristics And Cancellation Of Clutter In Passive Radar Based On Opportunity Transmitters

The passive radar based on opportunity transmitters is a new radar system, which usessignals from opportunity transmitters to detect and track targets instead of transmittingsignals itself. Also it has characteristics of the bistatic radar and meter-wave bandtransmitted wave, so this radar system can not be discovered by the reconnaissancereceiver and has powerful abilities of ECCM (Electronic Counter-Countermeasure),AARM (Anti Anti-Radiation Missile) and anti-stealthy targets. However, in this radarsystem, the clutter (including direct signal, multipath and ground clutter echoes) receivedby the radar receiver is so strong that target echoes will be masked and detection of targetswill be influenced badly. Therefore, clutter cancellation is very important to this radarsystem.Firstly, this paper discussed characteristics and suppression ways of clutter in passiveradar. Secondly, both commonly used statistical models of radar ground clutter echoes andmethods based on the ZMNL (Zero Memory Nonlinearity) approach to generate correlativeradar clutter were analyzed. Thirdly, a sequential approach was studied for disturbancecancellation in passive radar, which was based on projections of the received signals in asubspace orthogonal to disturbance. Finally, the sequential cancellation algorithm wassimulated to process both theory data and radar received data to prove its feasibility andvalidity.