Model-error-compensated reiterative adaptive beamforming on a physically shaded cylindrical array

Abstract

The authors formulate and compare beamspace and element-space formulations of Reiterative Superresolution (RISR) [S. D. Blunt et al., IEEE Trans. Aero. & Elec. Sys. 47, 332-346 (2011)] on a physically shaded cylindrical array. The beamspace adaptive approach minimizes computational load while use of a model-based structured covariance estimates enables adaptive beamforming with Doppler sensitive waveforms having little sample support. While structured covariance estimates reduce sample-support requirements and facilitate stable inversion, they also introduce degradation due to model-mismatch errors. In space-time adaptive processing (STAP), covariance matrix tapers (CMT) have been used to counter the effects of off-axis arrivals and other forms of model mismatch [J. R. Guerci, Space-Time Adaptive Processing for Radar (Artech, 2014)]. In adaptive pulse compression, CMT have been used to increase range sidelobe suppression in the presence of Doppler [T. Cuprak, M.S. Thesis (2013)]. In this work, we have formulated CMT to address model mismatch by accounting for interbeam arrivals. We also consider the degree to which CMT can be used to address model-mismatch in RISR resulting from the physical shading effects on the directionality of elements in a large cylindrical array. [Portions of this material are based upon work supported by the Naval Sea Systems Command.]