With funding from multiple agencies, we are producing improved, enhanced-resolution, gridded passive microwave ESDRs for monitoring cryospheric and hydrologic time series.
Previously available global gridded passive microwave data sets served a diverse community of hundreds of data users, but did not meet many requirements of modern ESDRs or CDRs, most notably in the areas of intersensor calibration and consistent processing methods. The original gridding techniques were relatively primitive and were produced on grids that are not easily accommodated in modern software packages. Further, since the time that the first Level 3 data sets were developed, the Level 2 passive microwave data on which they were based have been reprocessed as Fundamental CDRs (FCDRs) with improved calibration statistics. Our initial NASA MEaSUREs project addressed a great need to regenerate gridded Level 3 products using improved techniques from these modern Level 2 FCDRs.
Using validated, state-of-the-art interpolation methods, we reprocessed the gridded data sets, using the most mature available Level 2 satellite passive microwave records from 1978 to the present. We produced the complete data record from SMMR, SSM/I-SSMIS and AMSR-E in a single, enhanced-resolution gridded passive microwave ESDR. The MEaSUREs Calibrated Enhanced-Resolution Passive Microwave Daily EASE-Grid 2.0 Brightness Temperature ESDR, Version 1 (CETB) ESDR uses the latest improvements to the Level 2 SSM/I- SSMIS and AMSR-E data record. This data set is update daily in near real-time. Early adopters and current users are providing favorable feedback on how the the new, gridded ESDR is providing new insights in many applications. We are pleased to report that, as of 2021, our most recent funding is supporting efforts to add AMSR2 to the list of supported sensors.
With additional funding from the NASA Terrestrial Hydrology research program, we have also produced a companion data set with enhanced-resolution grids of Soil Moisture Active Passive (SMAP) brightness temperatures. The SMAP Radiometer Twice-Daily rSIR-Enhanced EASE-Grid 2.0 Brightness Temperatures, Version 2 data set contains twice-daily, enhanced-resolution brightness temperature data derived from the SMAP radiometer. SMAP data have been produced on 25 and 3.125 km EASE-Grid 2.0 projections for compatibility with the original CETB ESDR, and are also available on 36, 9, and 3 km grids for compatibility with the standard SMAP gridding resolutions. SMAP CETB data are now updated daily, in near real-time.