Exploiting array motion for augmentation of co-prime arrays

In this paper, we combine concepts from synthetic aperture processing and non-uniform linear array theory. Our objective is to use array motion to synthesize an array that can achieve the performance of a filled uniform linear array (ULA), but with fewer sensors than required for spatial Nyquist sampling. The class of physical arrays we use for synthesis are co-prime arrays constructed by nesting under-sampled ULA's with co-prime inter-element spacings. In particular, we use array motion to fill in missing co-array spacings. For co-prime M and N, a physical array of M + 2N - 1 sensors plus modest array motion is used to achieve a filled co-array corresponding to approximately 2MN elements. This facilitates spatial spectral estimation via non-adaptive beamforming over an extended aperture with low sidelobe performance.