High-resolution range-Doppler processing by coherent block-sparse estimation

This work contemplates advanced signal processing techniques for narrow band pulsed radar systems. If we assume a sparse scene of point-like targets and formulate the data model for the received signal in Fourier space, we can produce a block sparse estimation problem for the range profile spectra in all relevant Doppler channels. The range profile spectra are jointly estimated by coherent versions of block matching pursuit and basis pursuit algorithms. Then, in each Doppler channel, we compute the delays using a parametric high-resolution method. The mixed sparse/parametric approach overcomes the disadvantages of matched filters concerning resolution and ambiguities and has less computational complexity than full two-dimensional sparse estimation methods. We show results from numerical simulations and experimental measurements recorded with a passive bistatic radar using Global System for Mobil Communications (GSM) base stations as illuminators of opportunity.