Multiband chirp synthesis for frequency-hopped FMCW radar

This paper presents a method for increasing radar range resolution by stitching together non-contiguous frequency-hopped FMCW radar sweeps across different dwells. The work extends previous bandwidth extrapolation methods, designed for radar imaging of space-based objects, to applications involving clutter-dominated downward-looking radars. Multiband chirp synthesis (MCS) uses an AR model for the de-chirped radar return in frequency-separated sub-bands across multiple dwells to interpolate missing fast-time data. The method aims to achieve range resolution commensurate with the full frequency-hopped band of the radar rather than the much narrower sub-bands used during each dwell. Both pre- and post-Doppler MCS methods are discussed. Real data results are presented using a 2.4 GHz laboratory radar to synthesize a 600 MHz bandwidth return from multiple fractional sub-band dwells.