An efficient orthorectification of a satellite SAR image used for monitoring occurrence of disaster
An efficient orthorectification of a satellite SAR image used for monitoring occurrence of disaster
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用于监测灾害发生的卫星SAR图像的高效正射校正
DOI：
10.1109/iwait.2018.8369771
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Katsumi Tadamura
中科院分区：
文献类型：
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作者：
Risa Umemura;Toshikazu Samura;Katsumi Tadamura
合成孔径雷达（SAR）是一种主动式传感器，它可以使我们在白天和黑夜都能获得卫星图像。此外，它还具有全天候观测的特点，因为它发射的L波段微波受云和雨的影响较小。ALOS-2上的PALSAR-2实现了高分辨率（3米）观测，目前正在日本作为卫星L波段合成孔径雷达运行。尝试利用卫星SAR图像的优势来监测自然灾害的发生。PALSAR-2倾斜向下发射微波，并接收入射微波在地球表面的后向散射部分作为观测数据。因此，与使用从天顶拍摄的卫星照片不同，仅用卫星合成孔径雷达图像仅通过一瞥就很难确定灾害的发生。此外，由于卫星SAR图像是地理编码图像，因此地球上的实际位置受到与其被观测时间相对应的卫星位置的影响。因此，需要在基于所获得的卫星SAR图像分配正确数据的处理之后执行使用多个信息来判定自然灾害的发生的处理。这个过程称为正射校正。然而，由于用于检测自然灾害的发生的卫星SAR图像的大小相当大（大于1GB），因此需要有效的正射校正处理以快速地向自然灾害的检测处理提供输入数据。在本文中，我们提出了一种有效的正射校正过程的方法。
Synthetic aperture radar (SAR), which is one of active type sensors, allows us to obtain satellite images regardless day or night. In addition it has a feature of all-weather-observation because it emits L-band microwave which is less affected by clouds and rain. The PALSAR-2 aboard the ALOS-2, which achieves high-resolution (3m) observation, is now in operation as the satellite L-band SAR in Japan. The utilization of advantage of the satellite SAR image for monitoring the occurrence of a natural disaster has been tried. The PALSAR-2 emits microwave obliquely downward and receives the back-scattered portion of the incident microwave on the surface of the earth as the observed data. Accordingly, it is quite difficult to decide the occurrence of disaster only with the satellite SAR image by just glancing unlike using a satellite photograph taken from the zenith. In addition, since the satellite SAR image is geocoded image, the actual position on the earth is affected by the location of the satellite corresponding to the time it was observed. Therefore, the process deciding the occurrence of natural disaster using plural information is required to be carried out after a process assigning a correct data based on the obtained satellite SAR image. This process is called orthorectification. However, since the size of the satellite SAR image which is used for detecting occurrence of natural disaster is quite large (larger than 1 GB), an efficient orthorectification process is required to rapidly provide an input data to the detecting process of natural disaster. In this paper we propose a method for an efficient orthorectification process.