System Reliability Optimization Of Thinned Linear Arrays In Microwave Interferometric Radiometers

As a receiver of high sensitivity,microwave radiometer can detect or image the brightness temperature of the objects whose temperature is higher than absolute zero.This passive radiometric technique has a broad applications in the area of radio astronomy,remote sensing and safety inspection.By interferometric technique from a set of pairs of antennas,the synthetic aperture interferometric radiometers(SAIR)will measure the visibility function in the spatial frequency domain and then reconstruct the estimated brightness temperature(TB)of the observed scene with inverse algorithms.This kind of method,which synthesizes a real aperture by several small sized antennas,achieves the high spatial resolution as well as prevents the complexity of large real aperture antenna.It also provides the reconstructed image without scanning,which settles the problems among several systematic metrics,such as spatial resolution,sensitivity and time of imaging.As a significant technology of SAIR,the design and optimization of antenna array achieves the demanded solutions through establishing the mathematic model,optimization or combinatorial design.It determines the distribution of baselines and then affect the performance of reconstruction.In this paper,we try to solve the problem of system reliability,which is a crucial metric in SAIR.In recent radiometers,they just increased some redundant baselines of smaller ones because of the larger energy they obtain.However,it still lose the information of the observed scene.Therefore,we focus on the situation of one antenna's wreckage and try to study the system reliability as follows.We proposed the design model of two-fold redundancy linear array(TFRLA),which will guarantee the completeness of the coverage of the baselines in spatial frequency even in harsh situation by increasing the redundant times of each baselines.Furthermore,the method to construct two-fold redundancy planar array is proposed and the results are compared with some special array,such as “cross” planar array and “square” planar array.Moreover,we proposed the multi-objective optimization of system reliability,radiometric sensitivity and spatial resolution,which have crucial influence on reconstructed image.Under the circumstance of ensuring the system reliability,a set of Pareto solutions can be found by the state-of-the-art optimization algorithms.