An efficient array calibration method on underwater high resolution direction-finding

A novel and practical approach of array calibration in underwater high-resolution direction finding is presented to alleviate the effect of different errors generated in underwater array processing system. It is different from other algorithms in that the array manifold used in subspace-based methods is obtained through automatic measurement instead of using the theoretical value. It can efficiently calibrate the errors of gain, phase, mutual-coupling, position of sensors, and other errors generated by the array and sensors even if they are direction dependent. A spatial smoothing technique is employed and so the method is effective no matter if the sources are correlated or uncorrelated. It is also proved by the experiment that spatial smoothing is beneficial to reduce some errors. Several experimental results are provided to verify the efficiency of the new calibration method