Hans Hellsten

Autofocus in fast factorized backprojection for processing of SAR images when geometry parameters are unknown

This paper introduces a new autofocus method for high-resolution SAR systems. The new method relies on varying antenna path parameters, i.e. the cause of the focusing problem. The variation and determination of antenna path parameters is computed and structured by incorporating the method into the framework of fast factorized backprojection, and thus also blending deterministic focus and autofocus into one method. The new autofocus has been tested with wavelength-resolution SAR data with good results.

DVB-T interference cancellation in radar signal processing

In this paper, a novel filter for cancellation of DVB-T interference in low-frequency synthetic aperture radar systems is presented. The filter relies on using the pilots in the DVB-T signal to estimate the communications channel between the broadcast antenna and the flying radar system. Then, by decoding and re-coding the interference signal, it can be subtracted from the combined radar and TV signal. Simulation results indicate good performance in relevant signal-to-interference ratios.