Analysis of Kinematic Model Effects on SAR ECM

Abstract

Spotlight synthetic aperture radar (SAR) provides a high-resolution remote image- formation capability for airborne platforms. SAR image formation processes exploit the amplitude, time, and frequency shifts that occur in the transmitted wave- form due to electromagnetic propagation and scattering. These shifts are predictable through the SAR forward model which is dependent on the waveform parameters and emitter flight path. The approach to develop an electronic countermeasure (ECM) system that is founded on the SAR forward model implies that the ECM system should alter the radars waveform in a manner that produces the same amplitude, time, and frequency shifts that a real scatterer would produce at a desired location. A collection of such scatterers would be capable of forming a larger collective energy distribution in the final image. However, since the forward model is dependent on the radar platform’s kinematic model, the jamming energy distribution created from a forward-model based ECM system will inherently have some level of sensitivity to kinematic error. This work uses an entropy- based image similarity metric and defined-accuracy Monte Carlo simulations in order to assess the effect of the kinematic model on the resultant jamming energy distribution.