Superresolution Performance of Different Spatial Smoothing Methods for Short Uniform Linear Array

Radar withuniform linear antenna array is commonly used to measure the angle of the target. The superresolution ability is of significant importance in applications where the array size is limited and the targets are crowded. In this letter, we test the superresolution performance of a six-element array by field data using two trihedral corner reflectors set on the ground. The spatial smoothing methods with different subaperture sizes are compared, and a new spatial smoothing method using interlaced subaperture is proposed. The interlaced subaperture has larger effective aperture size and independent noise matrix, which leads to better superresolution performance. Its computational complexity is smaller than the successive subaperture due to the smaller size of the data matrix. Results show that two reflectors with angular separation of about half the Fourier limit can be resolved with high probability when the peak signal-to-noise ratio is about 35 dB.