高精度与高稳定性卫星海洋盐度辐射计设计

发布时间：2018-07-06 19:19

本文选题：综合孔径辐射计 + 空间分辨率　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：L波段的热辐射对海表盐度敏感，，但对应波段的被动式辐射计在一定空间分辨率要求下需要相当长的天线，通过采用综合孔径技术可以解决天线的问题。现有卫星辐射计广泛采用Y型天线阵列获取二维空间分辨率，通过改变天线阵列形状或阵列间距进一步改进辐射计性能时，研究发现Y型阵列的空间分辨率在不发生空间谱混叠时是最优的。通过对二维信号采样形式的推广，分析发现任意均匀或非均匀的二维天线阵列中，Y型阵列都是最优的。并且不增加天线阵元只改变阵元间距时，空间分辨率和灵敏度性能之间存在矛盾。因此，将超综合孔径辐射计和一维综合孔径辐射计相结合，本文中提出了二维超综合孔径方案，并讨论其与镜像综合孔径技术的可结合性。二维超综合孔径辐射计对可视度函数分别进行匹配滤波与干涉测量处理，但顺轨与交轨方向的相位关系会发生相位混叠而导致无法提取亮温信息。使用角度预处理型的匹配滤波可以解决此问题并实现二维的空间分辨，且与一维超综合孔径辐射计类似，此辐射计中不存在增加阵元间距时的不确定性矛盾。仿真结果证明，二维超综合孔径辐射计可以在取得高空间分辨率的同时，取得优于传统Y型阵列的灵敏度，实现高精度高分辨率的盐度辐射计设计。
[Abstract]:The thermal radiation in L-band is sensitive to the salinity of sea surface, but the passive radiometer in corresponding band needs a long antenna under certain spatial resolution. The problem of antenna can be solved by using synthetic aperture technique. The existing satellite radiometers widely use Y-shaped antenna arrays to obtain two-dimensional spatial resolution. When the antenna array shape or array spacing is changed to further improve the radiometer performance, It is found that the spatial resolution of Y-type arrays is optimal when there is no spatial spectral aliasing. By extending the sampling form of two-dimensional signal, it is found that the Y type array is optimal in any uniform or non-uniform two-dimensional antenna array. Moreover, there is a contradiction between spatial resolution and sensitivity when the space between the array elements is changed without increasing the antenna elements. Therefore, by combining the ultra-synthetic aperture radiometer with the one-dimensional synthetic aperture radiometer, a two-dimensional super-synthetic aperture scheme is proposed, and the feasibility of combining it with the mirror synthetic aperture technique is discussed. The two dimensional super-synthetic aperture radiometer performs matching filtering and interferometric measurement on the visibility function, but the phase relationship between the orbit and the interorbit direction will occur phase aliasing, which makes it impossible to extract the bright temperature information. This problem can be solved and two-dimensional spatial resolution can be realized by using the matched filtering of angle preprocessing type, and it is similar to the one-dimensional super-synthetic aperture radiometer. There is no uncertainty contradiction in this radiometer when increasing the spacing of array elements. The simulation results show that the two-dimensional super-synthetic aperture radiometer can obtain high spatial resolution and achieve better sensitivity than the traditional Y array, and achieve the design of high-precision and high-resolution salinization radiometer.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P715.6

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