SMAP Enhanced-Resolution Scatterometer and Synthetic Aperture Radar Image Products

Abstract

The MEaSUREs Calibrated Enhanced-Resolution Passive Microwave Daily EASE-Grid 2.0 Brightness Temperature (CETB) Earth Science Data Record and the SMAP Twice-Daily rSIR-Enhanced EASE-Grid 2.0 Brightness Temperature (SETB) Data Set provide an extensive multi-instrument, multi-decadal, time series of global enhanced-resolution microwave radiometer image products. The Earth-based CETB and SETB archives are generated using swath-based multi-frequency micro-wave brightness temperature (TB) observations collected by the Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR), the Special Sensor Microwave/Imager (SSM/I) and Special Sensor Microwave Imager/Sounder (SSMIS) series, the Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E), and the Soil Moisture Active Passive (SMAP) microwave radiometer. In this paper, we describe new global SMAP enhanced-resolution scatterometer and synthetic aperture radar (SAR) image products that augment the CETB and SETB archives. Earth-based, morning and evening images are generated using swath-based L-band (1.26 GHz) radar backscatter (σ°) observations and previous developed image reconstruction techniques. The available image products include cylindrical and azimuthal projection scatterometer and SAR σ° images with 1- and 3-day imaging intervals, and azimuthal projection scatterometer σ° images with an 8-day imaging interval that have been further corrected for incidence and azimuth angle variation over the Greenland and Antarctic ice sheets. These σ° image time series are compatibly-gridded with CETB and SETB T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">B</sup> image time series to support a wide variety of geophysical applications.