毫米波综合孔径辐射图像平均噪声功率特性

Characteristic of average noise power for millimeter-wave synthetic aperture radiometric image

针对强点源目标探测时灵敏度近似解析值与实际值偏差较大,不利于成像探测系统的性能表征问题,从毫米波综合孔径辐射图像全局入手,应用矩阵理论对图像平均噪声功率进行研究.建立了图像平均噪声功率与系统参数之间的关系,在此基础上提出均方灵敏度的概念.仿真结果表明:均方灵敏度受观测场景亮温分布的影响小,仅依赖于系统参数,更适合表征毫米波综合孔径成像探测系统性能.

Sensitivity of a millimeter-wave synthetic aperture radiometric imaging detection system de- pends on the brightness temperature distribution of the observed scene. In addition, the approximate analytic value of sensitivity deviates from the actual value greatly for the detection of the point source with high brightness temperature. For the above problem, the average noise power of the whole image was selected as the breakthrough point, and it was studied through the matrix theory. The relation- ship between the average noise power and the system parameters was established. Based on it, the concept of root-mean-square sensitivity was proposed. The simulation results indicate that the root- mean-square sensitivity only depends on the system parameters, and it is more suitable for the charac- terization of the performances of millimeter-wave synthetic aperture imaging detection system.