Hybrid radar waveform design utilizing complementary phase coding and linear frequency stepping for achieving improved slant range resolution in a synthetic aperature radar

A hybrid radar waveform design is presented for achieving improved slant range resolution in a synthetic aperture radar system. The hybrid waveform consists of K repetitions of L complementary phase coded pulses with linearly increasing carrier frequency from repetition to repetition. Processing of this frequency stepped, phase coded waveform consists of matched filtering on a pulse-by-pulse basis followed by amplitude weighting and coherent summation. Three types of complementary phase codes are analyzed with coder and decoder structures modeled by finite impulse response digital filters. Computationally efficient decoder structures are identified using the concept of a matched digital filter. The composite ambiguity function is defined and computed for several hybrid waveform examples.