Suppression of Doppler ambiguities for linear sparse arrays

A key trade-off in airborne or spaceborne synthetic aperture radar (SAR) design involves the pulse repetition frequency (PRF) and the number and location of range and Doppler ambiguities. The associated design issues are complicated further when the system involves a sparse array. A methodology is formulated based on selecting the PRF to avoid range ambiguities in the envelope mainbeam. The effects of the Doppler ambiguities falling within the envelope mainbeam are mitigated by using an optimal algorithm to generate weights that place s in the pattern of the (sparse or contiguous) array in the directions of the Doppler ambiguities. This approach can be used for the analysis and design of airborne or spaceborne SAR systems with contiguous or sparse arrays.