Iceberg signatures and detection in SAR images in two test regions of the Weddell Sea, Antarctica
Iceberg signatures and detection in SAR images in two test regions of the Weddell Sea, Antarctica
复制标题
DOI：
10.3189/2012j0g11j020
复制
发表时间：
2012
影响因子：
3.4
通讯作者：
Christine Wesche;W. Dierking
中科院分区：
文献类型：
--
作者：
Christine Wesche;W. Dierking
建立了一种基于像素的方法，用于自动识别不同季节和不同海冰条件下获取的卫星合成孔径雷达（SAR）图像中的冰山。这尤其包括较小的冰山（纵轴 100m 至 18.5 km）。使用 Envisat Advanced SAR (ASAR) 的 HH 偏振图像和欧洲遥感卫星 2 (ERS-2) SAR（VV 偏振）图像对位于南极洲威德尔海的两个测试区域进行了调查。前者提供了 2006 年全年的一系列图像模式和宽幅模式数据。ERS 数据是在 2000-03 年春季和夏季在南极半岛尖端附近采集的。 IM 图像中可识别的冰山最小尺寸<0.02km2。分别确定冰山、海冰和开阔水域的雷达后向散射系数。我们证明，将冰山与其周围环境（海冰或开阔水域）分离的误差取决于气象、海洋学和海冰条件。此外，SAR 图像的预处理（例如去斑）也会影响冰山识别。我们的测试地点无法证实检测精度随季节变化的差异，但正如其他调查结果表明的那样，一般来说必须予以考虑。
A pixel-based methodology has been established for automatic identification of icebergs in satellite synthetic aperture radar (SAR) images acquired during different seasons and for different seaice conditions. This includes, in particular, smaller icebergs (longitudinal axis 100m to 18.5 km). Investigations were carried out for two test regions located in theWeddell Sea, Antarctica, using images of the Envisat Advanced SAR (ASAR) at HH polarization and of the European Remote-sensing Satellite-2 (ERS-2) SAR (VV-polarized). From the former, a sequence of Image Mode and Wide Swath Mode data are available for the whole of 2006. The ERS data were acquired around the tip of the Antarctic Peninsula in spring and summer months of the years 2000–03. The minimum size of icebergs that could be identified in the IM images was <0.02km2. Radar backscattering coefficients of icebergs, sea ice and open water were determined separately.We demonstrate that the error in separating icebergs from their surroundings (sea ice or open water) depends on meteorological, oceanographic and sea-ice conditions. Also the pre-processing of the SAR images (e.g. speckle reduction) influences iceberg recognition. Differences in detection accuracy as a function of season could not be substantiated for our test sites, but have in general to be taken into account, as results of other investigations indicate.