Doppler aliasing reduction in SAR imagery using stepped-frequency waveforms

A new technique for reducing Doppler aliasing artifacts in Synthetic Aperture Radar (SAR) imagery is proposed. The technique uses Continuous Wave (CW) transmission of randomised Stepped-Frequency (SF) waveforms to generate a simple, but effective approximation of a 2-D sinc-squared ambiguity function. This approach places Doppler aliasing artifacts at Doppler filter nulls, effectively removing them from the matched filtered target echoes. The paper presents representative 1-D range profiles illustrating the desired Doppler filtering behaviour.