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NASA SIR-C Survey Imagesand Precision Processing Requests Sample image with
annotation.SIR-C (Spaceborne Imaging Radar-C) is an imaging radar system launched aboard the NASA Space Shuttle twice in 1994, SIR-C's unique contributions to Earth observation and monitoring are its capability to measure, from space, the radar signature of the surface at two different wavelengths and make measurements for different polarizations at those wavelengths. The EDC DAAC is distributing SIR-C processed Survey and Precision data, and is accepting requests for precision processing. SIR-C image data will help scientists understand the physics behind some of the phenomena seen in radar images at just one wavelength/polarization, such as those produced by SeaSAT. Investigators on the SIR-C/X-SAR Science team will use the radar image data to make measurements of: Vegetation type, extent and deforestation; Soil moisture content; Ocean dynamics, wave and surface wind speeds and directions; Volcanism and tectonic activity; Soil erosion and desertification. Survey Data ProductsSIR-C Survey products are available from the EDC DAAC via anonymous FTP using the DAAC Data Distribution System (DDS). Data from a single data_take (image swath) may be selected by [ground] track name, date, or geographic location. Note that the site and track names describe a target that the ground track passes through. The coverage maps can be used to help refine which part of the ground track or data_take contains the target of interest. All Survey data from the first mission (CD-ROM numbers S2, 1 - 57) and second mission (CD-ROM numbers 1 - 67) are available. Precision Data Processing Requests
This interface has been modified to allow users to place requests to have Precision data processed on demand. A third option has been added to the Data_Take display page to allow users to submit a precision processing request for an image segment by filling out an online order form. All new Precision data will be processed along image segment boundaries only. Currently the DAAC is only processing standard single look (SLC) and standard multi-look (MLC) Precision products. In the future additional Precision products will be offered in a phased implementation based on user demand. The SIR-C radar has various modes of operation which are different combinations of frequency and polarization (see Mode Table). Modes 1 through 16 were the primary modes of operation. Not every polarization and every frequency were acquired on each data_take. Different modes were used for each data_take depending on the primary science goal of the data_take. For example, geology data_takes were often taken in Mode 11 which provides dual frequency and dual polarization data and a swath width of approximately 30-50 km thereby providing good data coverage. Ecology data_takes were often taken in mode 16 which is dual frequency and quad polarization; due to the greater amount of data collected in mode 16, the swath width is narrower and is typically 10-25 km wide. Many sites were imaged in more than one mode on different data_takes (passes). The mode information is included in the DTHDR.TXT text file posted with the survey data for each data_take. The mode information is found on line #6. After an order has been placed, a confirmation E-mail will be sent out to verify that the order was received. This E-mail will contain the processing run number(s) assigned, the data_take, and the site name. DAAC User Services will only contact you if there is a problem with your order.
Note: This is a prototype system. Changes and improvements are being made. More information is available in the following documents:
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