Categorization of Jammers for Spaceborne SAR Systems

SAR systems are widely used in military, scientific, and commercial missions. The use of these systems makes jamming a focal point for users. To reduce the impact of jamming, this phenomenon needs to be better understood. This paper suggests a method for the categorization of jamming mechanisms in synthetic aperture radar (SAR) systems that builds on the physics of SAR acquisitions and jamming signals. It investigates the effects of different types of jammers on SAR images and systematically categorizes them. The categorization is based on the mathematical representation of the physics of the jamming signal and the SAR image formation process. For all suggested categories, jammers are simulated based on a simple, generic scene to investigate their effects on the resulting SAR image. These effects can vary across a wide range-from adding background noise to unfocused responses similar to point target scattering. Moreover, an intelligent jammer is even able to generate false targets virtually or to reduce the signal intensity of real targets by retransmitting signals fully adapted to the image acquisition scenario. Categorizing jammers is a bottom-up task best based on physics. It will be essential in the future when the sky is crowded with constellations of satellites and interference levels increase significantly and become commonplace.