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The linear step frequency pulse compression waveform suffers from a) range ambiguities due to periodicities in the discrete Fourier transform (DFT) and b) signal-to-noise ratio (SNR) losses due to amplitude weighting used to suppress nominal range sidelobes. Mark Waibridge of DERA Malvern, U.K., has proposed a nonlinear step frequency waveform which is derived from sampling a Doiph Chebyshev weighting function. The waveform does not exhibit range ambiguities and achieves low near-in sidelobes without incurring the SNR loss associated with conventional sidelobe suppression techniques. This paper assesses an implementation of the non-linear step frequency waveform by quantifying range sidelobes, range resolution, and range-Doppler coupling. The waveform has application in ultra-high range resolution profile generation.

Pulse compression waveforms and processing techniques for high-resolution signature formation are typically constrained by hardware limitations and target motion. This paper serves as a summary comparison of three modern pulse compression techniques: 1) linear frequency modulation (matched filtering), 2) stretch processing, and 3) stepped frequency waveforms, that are designed to perform under different hardware limitations. However, tradeoffs exists between the three techniques which limit range window sizes, result in range aliasing, define minimum sampling rates and instantaneous bandwidths, and define range-Doppler ambiguities and distortions. This paper focuses on the mathematical development of the three techniques and relates the results to hardware requirements and range-Doppler ambiguities/distortions.

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