星载微波散射计高分辨率σ~0图像重构方法研究

Study of Image Reconstruction Techniques for Spaceborne Scatterometer

针对我国海洋二号卫星微波散射计(HaiYang-2Scatterometer,HY2-SCAT)数据存在的空间分辨率较低、无法满足对于地球冰冻圈、生物圈探测需求的问题,以其数据拓展应用为目标,开展了微波散射计高分辨率后向散射系数(σ0)图像重构技术仿真研究。采用仿真的方法实现并对比了AART(Additive Algebraic Reconstruction Technique)、MART(Multiplicative Algebraic Reconstruction Technique)、SIR(Scatterometer Image Reconstruction)3种分辨率增强的图像重构算法,得出了AART算法没有噪声抑制能力、MART算法噪声抑制能力较弱、SIR算法具有较强的噪声抑制能力,能更好地重构图像,达到分辨率增强效果的结论。然后采用HY2-SCAT测量L1B数据对结论进行了验证,重构了岛屿的地貌特征,得到了分辨率增强、细节丰富、边界清晰的重构图像;重构后的图像还可以应用于植被、冰盖和台风观测等地球地理学研究领域。

High-resolution reconstruction techniques are investigated for Hai Yang-2Scatterometer(HY2-SCAT)backscatter measurements for a variety of application purposes including land and polar ice detection and the studies of cryophere and biosphere.Three resolution enhancement algorithms,including Additive Algebraic Reconstruction Technique(AART),Multiplicative Algebraic Reconstruction Technique(MART)and Scatterometer Image Reconstruction(SIR),are compared by simulation approach.The results that SIR has the best performance in noise suppression and resolution enhancement of the backscatter measurements than AART and MART algorithms.This study is verified using HY2-SCAT Level-1B(L1B)backscatter measurements.The !0measurements over some sites with particular backscattering characteristics(e.g.islands)are reconstructed.