SIR-C (Spaceborne Imaging Radar-C)

The Spaceborne Imaging Radar-C (SIR-C), launched a decade after its predecessors (SIR-A and SIR-B), was integrated with the German-built X-Band Synthetic Aperture Radar (X-SAR) to capture images of Earth across three different wavelengths.The SIR-C instrument flew on two separate shuttle missions (STS-59 and STS-68, respectively) and collected data on terrestrial soil moisture content, ocean dynamics, volcanism and tectonic activity, and soil erosion and desertification.The SIR-C/X-SAR payload, a collaborative effort between NASA/JPL, DARA/DLR, and the Italian Space Agency (ASI), was carried aboard the Space Shuttle Endeavour as part of NASA’s Mission to Planet Earth. This experiment marked a significant progression in NASA’s SIR program, which originated with Seasat in 1978 and continued with SIR-A in 1981 and SIR-B in 1984. It also extended Germany’s imaging radar program, which began with the Microwave Remote Sensing Experiment (MRSE) on the first SPACELAB mission in 1983.ASF has made many of SIR-C data available to the public as beta products.SIR-C Product GenerationThe SLC images are stored in GeoTIFF format as complex floating-point values. The files are georeferenced, i.e., they contain ground control points (GCPs) that can be used to geocode the image using tools such as gdalwarp.Browse images are generated in JPG format.ReferencesFreeman, A., Alves, M., Chapman, B., Cruz, Kim, Y., Shaffer, S., Sun, J., Turner, E. and Sarabandi, K., 1995. SIR-C Data Quality and Calibration Results, IEEE Transactions on Geoscience and Remote Sensing, 33(4):848-857.空间成像雷达-C（SIR-C）型雷达，继其前辈（SIR-A和SIR-B）之后十年发射升空，与德国制造的多频段合成孔径雷达（X-SAR）相结合，用以捕捉地球表面的图像，跨越了三种不同的波长。SIR-C仪器分别搭载于两次独立的航天飞机任务（分别为STS-59和STS-68）进行飞行，并收集了有关陆地土壤湿度、海洋动力学、火山活动与构造运动，以及土壤侵蚀与荒漠化的数据。SIR-C/X-SAR有效载荷为NASA/JPL、DARA/DLR与意大利航天局（ASI）的协作成果，作为NASA地球行星任务的一部分，搭载于航天飞机“奋进号”上。此次实验标志着NASA SIR项目的重要进展，该项目起源于1978年的Seasat，后继以1981年的SIR-A和1984年的SIR-B。同时，它也拓展了德国的成像雷达项目，该项目始于1983年首次SPACELAB任务上的微波遥感实验（MRSE）。美国地质调查局（ASF）已将SIR-C数据的大部分作为预览产品对公众开放。SIR-C产品生成中，SLC图像以GeoTIFF格式存储，以复数浮点值形式存在，且已进行地理编码，即包含可用于通过诸如gdalwarp等工具进行图像地理编码的地面控制点（GCPs）。浏览图像则以JPG格式生成。参考文献：Freeman, A., Alves, M., Chapman, B., Cruz, Kim, Y., Shaffer, S., Sun, J., Turner, E. and Sarabandi, K., 1995. SIR-C Data Quality and Calibration Results, IEEE Transactions on Geoscience and Remote Sensing, 33(4):848-857.