A high-resolution angle estimation method for distributed aperture arrays

To achieve accurate Direction-of-Arrival (DOA) estimation of far-field targets, distributed aperture arrays are employed in this work. Compared with traditional aperture array radars, distributed aperture arrays can expand the physical aperture of the array, leading to improved angle estimation performance. However, the spacing between sub-arrays in distributed aperture arrays is significantly greater than half a wavelength, violating the Nyquist sampling theorem. This results in multiple grating lobes in the echo directional diagram, causing ambiguity in angle estimation. A novel high-resolution angle estimation method based on subarray angle estimation for distributed aperture arrays is proposed. The method follows a two-step coarse-fine process and is applicable to arbitrarily configured distributed arrays and effectively addresses the issue of angle ambiguity. The estimation performance surpasses existing methods, achieving an estimation error of about 0.04° at a signal-to-noise ratio of 10 dB.