A-priori Information Driven Detection of Moving Objects for Traffic Monitoring by Spaceborne SAR

Abstract

This paper derives the theoretical background for upcoming dual-channel radar satellite missions to monitor traffic from space. As it is well-known, an object moving with a velocity deviating from the assumptions incorporated in the focusing process will generally appear both displaced and blurred in azimuth direction. To study the impact of these (and related) distortions in focused SAR images, the analytic relations between an arbitrary moving point scatterer and its conjugate in the SAR image have been derived and adapted to dual-channel satellite specifications. To be able to monitor traffic under these boundary conditions in real-life situations, a specific detection scheme is proposed. This scheme integrates complementary detection and velocity estimation algorithms with knowledge derived from external sources as, e.g., road databases