Passive Radar Clutter Modeling And Inhibition

The passive radar based on external illuminator is a new radar system. Not radiating electromagnetic wave and using FM broadcast electromagnetic wave to detect objects, this radar is not easy to be detected by electronic scouting system, and it has abilities of ECCM (Electronic Counter-Countermeasure), AARM(Anti Anti-Radiation Missile) and anti-stealthy targets. In this system radar, the very strong direct signal and multipath reflected clutter of the receiver device, as its character, will affect the detection of object very badly, and this character will reduce the detection probability of object and increase the probability of false alarm.Firstly, the structure of bistatic radar and the platform will be introduced. Secondly, that coherent correlation radar clutter can be generated by Zero Memory Nonlinearity, as the nonlinear relation between the correlation coefficient before and after nonlinear transform is known. Thirdly, the paper analyzes the total of intensity in the apparent distance scope under a simplification simulation, discussed the difference between the surface clutter and direct signal. And we explain the reason why we need the long time coherent accumulation to detect objects under the interference environment. Because the detecting performance of object based on bistatic system is greatly influenced by the direct signal and the multipath clutter. Finally this paper uses an effective algorithm based on passive radar's clutter canceling to overcome the problem. The presented algorithm employs the auxiliary receiving channel reference signal to adaptively cancel the direct signal and multipath clutter by using the fractional interpolated arrival time interval of such clutters.