干涉式微波辐射计成像算法以及天线阵采样方案分析

对旋转扫描干涉式微波辐射计成像算法进行研究,提出了基于伪极网格傅立叶变换的成像算法,利用一维插值以及一维FFT即可实现图像重建,既提高了成像精度,又保证了成像速度。以3种8单元天线排列方案阵为例,利用本文方法和基于线性插值的笛卡儿网格方法分别进行成像模拟,模拟结果验证了本文方法的优越性,同时表明天线阵排列方案对成像结果影响很大,天线阵基线均匀性越好,数量越多,成像质量就越好。直线阵无法实现基线数量与均匀性的统一,而平面阵可以在较好均匀性情况下实现最多的基线数,是天线阵排列的首选方案。

Imaging Algorithm and Antenna Array of Interferometric Microwave Radiometer

The imaging theory of rotary scanning synthetic aperture microwave radiometer is studied,and a new imaging algorithm based on pseudo-polar FFT is developed.The critical feature of the algorithm is that it involves only 1-D equispaced FFT and 1-D interpolation,so it is more fast and accurate for application.In order to validate this new algorithm and analyze the antenna array effects on image reconstruction,the imaging of three typical designs of 8 elements antenna array is simulated by the pseudo-polar FFT method and linear interpolation based Cartesian FFT method.The results illustrate the superior performance of the new method and also indicate that the baseline's uniformity and number have a great influence on the reconstruction,and the plane distributed antenna array is preferred rather than the linear distributed array for it has more baselines and good uniformity simultaneously.