Spatial Spectrum Estimation Calibration Algorithm In Microwave Radiation Receiving System

Microwave detection technology is a whole passive target detection technology which detect object's microwave radiation characteristics. Using that technology, radar is concealed, and difficult to be discovered, it works in any weather conditions and impact of battlefield smoke and dust.However, using single antenna to receive the microwave radiation is difficult to achieve a better spatial resolution, using antenna arrays and array signal processing could synthesis a number of small-size antenna to a large one, to enhance spatial resolution. However, the traditional array signal processing methods (such as: Synthetic Aperture algorithm) which spatial resolution depends on the length of the largest array antenna baseline. To further improve the resolution, spatial spectrum estimation methods in adaptive array signal processing can be applied to array of microwave radiation receiving system to achieve super-resolution target detection.But high-resolution spatial spectrum estimation algorithm is built on ideal array signal processing model, when inevitable actual errors exist, such algorithm performance rapidly declined, and even failure. This paper analysis and compares various mature spatial spectrum estimation calibration algorithm, find traditional single correct source gain-phase calibration method overlooked the inconsistencies between channels gain on the impact of noise. The signal that array of microwave radiation receiving system receive is weak, large channel gain needed, so gain inconsistencies exist inevitable, the impact of noise can not be ignored. Based on original algorithm, this paper improves the calibration algorithm by using the diagonal of self correlation matrix for the gain error, and least squares algorithm on the up-triangle part of matrix for phase error.This paper first simulate the traditional and improved calibration algorithm, confirmed that the improved calibration algorithm has the same efficient with traditional method in high SNR, but improved calibration algorithm works much better than traditional method in the low SNR. Validate the correctness of the theory is derived. Using improved single correct source gain-phase calibration method algorithm with MUSIC algorithm in the array of microwave radiation receiving system in target detection, a number of experimental results show that improved calibration algorithm is better than the traditional one. Finally, the spatial spectrum estimation algorithm is compared with other typical array signal processing algorithms in experiment results of target detection of microwave radiation signal, in small air object detection, it has better effect than Fourier algorithm, and at the same time has smaller costs, faster, and occupy less storage space than the G-Matrix algorithm.