Remote sensing of ocean surface winds with the special sensor microwave/imager

As part of a subcontract with the manufacturer of the Defense Meteorological Space Program (DMSP) special sensor microwave/imager (SSM/I), an operational wind speed algorithm was developed by Environmental Research and Technology, Inc. (ERT). The ERT algorithm is based on the “D‐matrix” approach, which seeks a linear relationship between measured SSM/I brightness temperatures and environmental parameters. D‐matrix performance was validated by comparing algorithm derived wind speeds with near‐simultaneous and colocated measurements made by offshore ocean buoys maintained by the National Oceanic and Atmospheric Administration. The DMSP accuracy requirement of ±2 m/s for wind speed predictions in the range of 3 m/s to 25 m/s was not obtainable with the original version of the D‐matrix, which had severe bias and scaling problems. Revisions to the algorithm made at the University of Massachusetts caused it to perform within specifications. Other topics include error budget modeling, alternate wind speed algorithms, and D‐matrix performance with one or more inoperative SSM/I channels.