Very High Resolution Spaceborne SAR Tomography in Urban Environment
Very High Resolution Spaceborne SAR Tomography in Urban Environment
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DOI：
10.1109/tgrs.2010.2050487
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发表时间：
2010-06
影响因子：
8.2
通讯作者：
Xiaoxiang Zhu;R. Bamler
中科院分区：
文献类型：
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作者：
Xiaoxiang Zhu;R. Bamler
合成孔径雷达层析成像（TomoSAR）将合成孔径原理扩展到仰角方向进行三维成像。它使用从略微不同的视角（仰角孔径）采集的多个图像叠加，通过对每个方位角范围像素的光谱分析，沿仰角方向重建反射率函数。新型的米分辨率星载SAR系统（TerraSAR-X和COSMO-Skymed）在城市地区和人造基础设施的层析成像重建方面提供了巨大的改进。高分辨率很好地适应了建筑物的固有尺度（楼层高度、窗户距离等）。本文以城市环境的TerraSAR-X射光数据为基础，论证了这些sar的层析成像潜力和可实现的质量。介绍了一种新的奇异值分解方法的wiener正则化方法，等效于极大后检估计，并将其推广到微分情况（4-D，即时空）。比较了不同的模型选择方案对分辨单元中散射体数的估计，证明了它们在实际中是适用的。给出了散射体高程和速度的两种参数估计算法。首先，通过像素TomoSAR从星载SAR数据中获得整个建筑综合体（包括其雷达反射率）的三维和4d重建，并提供了非常详细的细节。
Synthetic aperture radar tomography (TomoSAR) extends the synthetic aperture principle into the elevation direction for 3-D imaging. It uses stacks of several acquisitions from slightly different viewing angles (the elevation aperture) to reconstruct the reflectivity function along the elevation direction by means of spectral analysis for every azimuth-range pixel. The new class of meter-resolution spaceborne SAR systems (TerraSAR-X and COSMO-Skymed) offers a tremendous improvement in tomographic reconstruction of urban areas and man-made infrastructure. The high resolution fits well to the inherent scale of buildings (floor height, distance of windows, etc.). This paper demonstrates the tomographic potential of these SARs and the achievable quality on the basis of TerraSAR-X spotlight data of urban environment. A new Wiener-type regularization to the singular-value decomposition method-equivalent to a maximum a posteriori estimator-for TomoSAR is introduced and is extended to the differential case (4-D, i.e., space-time). Different model selection schemes for the estimation of the number of scatterers in a resolution cell are compared and proven to be applicable in practice. Two parametric estimation algorithms of the scatterers' elevation and their velocities are evaluated. First 3-D and 4-D reconstructions of an entire building complex (including its radar reflectivity) with very high level of detail from spaceborne SAR data by pixelwise TomoSAR are presented.