Airborne distributed array position calibration using sparse spatial-frequency accompanying flight MISO array

Abstract

Airborne coherent distributed array radar (DCAR) can greatly improve radar detection range and angle resolution. However, the time-variant property of airborne DCAR elements’ position strongly limits the application in real situations. In this paper, we developed a high-accuracy position estimation method for airborne DCAR systems with position errors using a single accompanying flight (AF) array. The basic principle is using a small array with a spatial sparse configuration to transmit a sparse-frequency multiple input single output (MISO) signal. Then airborne DCAR elements receive the signals and perform multi-channel demodulation and parameter estimation processing to obtain their distance and angle information relative to the AF array. The presented method estimates the position of all DACR elements with the single same array and thus various inaccordance between different transmit sources can be avoided. By using a spatial-frequency sparse array, the system complexity of the accompanying flight platform can be greatly reduced. Our method can obtain position estimates that are smaller than the operating wavelength, which ensures that sufficient performance can be obtained from coherent processing. Simulation results are given to demonstrate the effectiveness of the proposed method.