Engineering topics
Dunbar, R.
Publications and source records attributed to Dunbar, R..
Assessment of Version 4 of the SMAP Passive Soil Moisture Standard Product
NASAs Soil Moisture Active Passive (SMAP) mission launched on January 31, 2015 into a sun-synchronous 6 am6 pm orbit with an objective to produce global mapping of high-resolution soil moisture and freeze-thaw state every 2-3 days. The SMAP radiometer began acquiring routine science data on March 31, 2015 and continues to operate nominally. SMAPs radiometer-derived standard soil moisture product (L2SMP) provides soil moisture estimates posted on a 36-km fixed Earth grid using brightness temperature observations and ancillary data. A beta quality version of L2SMP was released to the public in October, 2015, Version 3 validated L2SMP soil moisture data were released in May, 2016, and Version 4 L2SMP data were released in December, 2016. Version 4 data are processed using the same soil moisture retrieval algorithms as previous versions, but now include retrieved soil moisture from both the 6 am descending orbits and the 6 pm ascending orbits. Validation of 19 months of the standard L2SMP product was done for both AM and PM retrievals using in situ measurements from global core calval sites. Accuracy of the soil moisture retrievals averaged over the core sites showed that SMAP accuracy requirements are being met.
A Multi-Pass Median Filter Technique to Remove Ambiguities in Retrieved Wind Fields from Spaceborne Scatterometer Data
In this paper we present a technique called the multi-pass median filter algorithm.
Improving the Sea Surface Wind Retrieval Algorithm for NASA Scatterometers Using Atmospheric Boundary Layer Models
The use of an atmospheric boundary layer (ABL) model is investigated to improve wind retrieval algorithms for NASA scatterometer projects.