Cosine Matching Imaging Method for Rotating Scanning Synthesis Aperture Imaging Radiometer

Millimeter-wave synthesis aperture imaging radiometer (SAIR) can realize high-resolution observations without requiring the real large aperture antenna. Among the SAIRs, the Rotating Scanning SAIR (RS-SAIR) with linear sparse array is a popular system with low redundancy and high reliability. However, due to the lack of matched imaging methods, its imaging precision is usually low. For improving its imaging precision, a novel Cosine Matching Imaging (CMI) method is proposed in this paper. In CMI method, according to the characteristic of rotating projection imaging, the angle-orientation image is constituted by the 1D projection images measured by RS-SAIR in a series of angles firstly. Then, according to the trajectory of the target in angle-orientation image, the pixel values of the brightness temperature image are extracted by cosine matching method from the angle-orientation image one by one. The simulation results demonstrate that the proposed CMI imaging method has higher reconstruction accuracy for the RS-SAIR.