Method for array calibration in high-resolution sensor array processing

With few exceptions, most high-resolution sensor array algorithms for direction of arrival (DOA) estimation are sensitive to the errors in the nominal array manifold. Deviations from the true array manifold, typically resulting from mutual coupling, array channels mismatch and sensor positioning errors, can seriously degrade the algorithms´ performance. Several array calibration algorithms have been reported in the literature; however, only a handful have addressed the problem of calibrating the errors in the array manifold that result from the combined effects of mutual coupling, sensor positioning error and mismatch in the array channels. This problem is addressed in the paper. By extending the array parametrisation to describe the deviations of the nominal array manifold from the actual array manifold, the array calibration problem considered can be posed as that of estimating the calibration matrix and sensor positions. The array calibration method proposed estimates the sensor positions and calibration matrix from a set of measured steering vectors. The usefulness and behaviour of the proposed calibration method are illustrated through simulated experiments