Parameter estimation based on Hough transform for airborne radar with conformal array

Abstract

Signal parameter estimation like direction of arrival (DOA), polarization and Doppler frequency for conformal arrays with a reasonable computational effort is cumbersome, because conformal arrays have complex steering vectors without Vandermonde structure but involves distinct antenna patterns. To this end, we propose a fast estimation algorithm which enjoys computational benefit stemming from processing in fractal dimension and the Hough transform. Firstly, we obtain rough DOA estimations via the Hough transform using the covariance matrix phases, on the basis of a devised systematic scheme of ambiguity resolving. Subsequently, polarization is obtained through a rank reduced problem with DOA substituted. Precision improves by iteration and alternative optimization between DOA and polarization. Thirdly, we calculate the Doppler frequency with the temporal covariance matrix. Simulations validate that the proposed algorithm outperforms existing algorithms for slightly lower computation complexity and sufficient precision.