Spaceborne Imaging Radar C-band (SIR-C)

Spaceborne Imaging Radar-C (SIR-C) is part of an imaging radar system that was flown on board two Space Shuttle flights (9 - 20 April, 1994 and 30 September - 11 October, 1994). The USGS distributes the C-band (5.8 cm) and L-band (23.5 cm) data. All X-band (3 cm) data is distributed by DLR.

There are several types of products that are derived from the SIR-C data:

Survey Data is intended as a "quick look" browse for viewing the areas that were imaged by the SIR-C system. The data consists of a strip image of an entire data swath. Resolution is approximately 100 meters, processed to a 50-meter pixel spacing. Files are distributed via File Transfer Protocol (FTP) download.

Precision (Standard) Data consists of a frame image of a data segment, which represents a processed subset of the data swath. It contains high-resolution multifrequency and multipolarization data. All precision data is in CEOS format.

The following types of precision data products are available:

Single-Look Complex (SLC) consists of one single-look file for each scene, per frequency. Each data segment will cover 50 kilometers along the flight track, and is broken into four processing runs (two L band, two C-band). Resolution and polarization will depend on the mode in which the data was collected. Available as calibrated or uncalibrated data.

Multi-Look Complex (MLC) is based on an averaging of multiple looks, and consists of one file for each scene per frequency. Each data segment will cover 100 km along the flight track, and is broken into two processing runs (one L band and one C band). Polarization will depend on the modes in which the looks were collected. The data is available in 12.5- or 25-meter pixel spacing.

Reformatted Signal Data (RSD) consists of the raw radar signal data only. Each data segment will cover 100 km along the flight track, and the segment will be broken into two processing runs (L-band and C-band).

Interferometry Data consists of experimental multitemporal data that covers the same area. Most data takes were collected during repeat passes within the second flight (days 7, 8, 9, and/or 10). In addition, nine data takes were collected during the second flight that were repeat passes of the first flight. Most data takes were also single polarization, although dual and quad polarization data was also collected on some passes. A Digital Elevation Model (DEM) is not included with any of the SIR-C interferometric data.

The following types of interferometry products are available:

Interferometric Single-Look Complex (iSLC) consists of two or more uncalibrated SLC images that have been processed with the same Doppler centroid to allow interferometric processing. Each frame image covers 50 kilometers along the flight track. The data is available in CEOS format.

Raw Interferogram product (RIn) involves the combination of two data takes over the same area to produce an interferogram for each frequency (L-band and C-band). The data is available in TAR format.

Reformatted Signal Data (RSD) consists of radar signal data that has been processed from two or more data takes over the same area, but the data has not been combined. Although this is not technically an interferometric product, the RSD can then be used to generate an interferogram. Each frame will cover 100 km along the flight track. The data is available in CEOS format.

太空成像雷达-C（Spaceborne Imaging Radar-C，简称SIR-C）是成像雷达系统的一部分，该系统曾在两次航天飞机任务中搭载飞行（1994年4月9日至20日和1994年9月30日至10月11日）。美国地质调查局（USGS）分发C波段（5.8厘米）和L波段（23.5厘米）数据。所有X波段（3厘米）数据由德国航空航天中心（DLR）分发。

从SIR-C数据中衍生出多种类型的产品：

调查数据旨在作为对SIR-C系统成像区域进行“快速浏览”的参考。该数据由整个数据条带的全幅图像组成。分辨率约为100米，处理至50米像素间距。文件通过文件传输协议（FTP）下载。

精度（标准）数据由数据段框架图像组成，代表数据条带经过处理的子集。它包含高分辨率的多频段和多极化数据。所有精度数据均采用CEOS格式。

以下类型的精度数据产品可供使用：

单视复数（Single-Look Complex，简称SLC）由每个场景每个频段的单个单视文件组成。每个数据段将覆盖飞行轨迹上的50公里，并分为四个处理运行（两个L波段，两个C波段）。分辨率和极化取决于数据收集的模式。数据可作为校准或未校准数据提供。

多视复数（Multi-Look Complex，简称MLC）基于多次视的加权平均，每个场景每个频段对应一个文件。每个数据段将覆盖飞行轨迹上的100公里，并分为两个处理运行（一个L波段和一个C波段）。极化取决于收集视的模式。数据以12.5米或25米像素间距提供。

重格式化信号数据（Reformatted Signal Data，简称RSD）仅包含原始雷达信号数据。每个数据段将覆盖飞行轨迹上的100公里，并分为两个处理运行（L波段和C波段）。

干涉数据由覆盖相同区域的实验性多时相数据组成。大多数数据采集在第二次飞行的重复飞行期间进行（第7、8、9天和/或第10天）。此外，在第二次飞行期间还采集了九次数据，这些数据是对第一次飞行重复飞行的重复飞行。大多数数据采集为单极化，尽管在某些飞行中也采集了双极化和四极化数据。SIR-C干涉数据不包含数字高程模型（DEM）。

以下类型的干涉产品可供使用：

干涉单视复数（Interferometric Single-Look Complex，简称iSLC）由经过相同多普勒中心频率处理的两个或更多未校准SLC图像组成，以允许干涉处理。每个框架图像覆盖飞行轨迹上的50公里。数据以CEOS格式提供。

原始干涉图产品（Raw Interferogram product，简称RIn）涉及在同一区域上对两个数据采集进行组合，以产生每个频段（L波段和C波段）的干涉图。数据以TAR格式提供。

重格式化信号数据（Reformatted Signal Data，简称RSD）由从同一区域的两个或更多数据采集中处理得到的雷达信号数据组成，但数据尚未组合。虽然这并非技术上的干涉产品，但RSD可以用于生成干涉图。每个框架将覆盖飞行轨迹上的100公里。数据以CEOS格式提供。