Background

RADARSAT is a Canadian satellite launched by NASA in November 1995. RADARSAT carries a synthetic aperture radar (SAR) that operates at C-band (5.3 GHz, 5.66 cm wavelength) and HH polarization. The SAR transmits a beam of energy toward the surface and detects the backscattered power, which is unaffected by clouds or darkness. The SAR data of the SHEBA region were downlinked at the Alaska SAR Facility (ASF) in Fairbanks and processed into images there.

All the images of the SHEBA region were acquired with the ScanSAR Wide B mode. The swath width is 460 km and the length of each image is 500 km. At full resolution, the pixel size is 50m. Medium resolution (100m) and low resolution (400m) images are also available. The images acquired for SHEBA have been geocoded into the SSM/I polar stereographic projection. This projection is based on the Hughes ellipsoid, is true at 70 N latitude, and is oriented so that the +X axis runs along 45 E longitude and the +Y axis runs along 135 E longitude.

The reason we have RADARSAT coverage of SHEBA at all is thanks to the NASA-funded RADARSAT Geophysical Processor System (RGPS). To support RGPS, ASF is acquiring an "Arctic Snapshot" every three to six days - complete RADARSAT coverage of the western Arctic Ocean. Since the SHEBA site was within the Arctic Snapshot region, SHEBA benefited from the frequent coverage without having to do any of the acquisition planning or scheduling.