Accession Number : ADA338999

Title :   Biweekly Maps of Wind Stress for the North Pacific from the ERS-1 Scatterometer 1992 - 1995

Corporate Author : WOODS HOLE OCEANOGRAPHIC INSTITUTION MA

PDF Url : ADA338999

Report Date : NOV 1997

Pagination or Media Count : 104

Abstract : The European Remote-sensing Satellite (ERS-1) was launched in July 1991 and contained several instruments for observing the Earth's ocean including a wind scatterometer. The scatterometer measurements were processed by the European Space Agency (ESA) and the Jet Propulsion Laboratory (JPL). JPL reprocessed (Freilich and Dunbar, 1992) the ERS-1 backscatter measurements to produced a 'value added' data set that contained the ESA wind vector as well as a set of up to four ambiguities. These ambiguities were further processed using a maximum-likelihood estimation (MLE) and a median filter to produce a 'selected vector.' This report describes a technique developed to produce time-averaged wind field estimates with their expected errors using only scatterometer wind vectors. The processing described in this report involved extracting regions of interest from the data tapes, checking the quality and creating the wind field estimate. This analysis also includes the derivation of biweekly average wind vectors over the North Pacific Ocean at a resolution of 0.50 x 0.50. This was done with an optimal average algorithm temporally and an over-determined biharmonic spline spatially. There have been other attempts at creating gridded wind files from ERS-1 winds, e.g., kriging techniques (Bentamy et al., 1996) and successive corrections schemes (Tang and Liu, 1996). There are several inherent problems with the ERS-1 scatterometer. Since this is a multidisciplinary mission, the satellite is flown in different orbits optimized for each phase of the mission. The scatterometer also shares several sub-systems with the Synthetic Aperture Radar (SAR) and cannot be operated while the SAR is in operation. The scatterometer is also a single-sided instrument and only measures backscatter along the right side of the satellite. The processing described here generates biweekly wind maps durin

Descriptors :   *SYNTHETIC APERTURE RADAR, *BACKSCATTERING, *REMOTE DETECTORS, *ARTIFICIAL SATELLITES, *SCATTEROMETERS, DATA BASES, FILES(RECORDS), ALGORITHMS, DATA PROCESSING, EUROPE, ORBITS, MEASUREMENT, GRIDS, REGIONS, ESTIMATES, MISSIONS, EXTRACTION, OCEANS, EARTH(PLANET), AMBIGUITY, NORTH PACIFIC OCEAN, WIND STRESS, CORRECTIONS, MAGNETIC TAPE.

Subject Categories : Acoustic Detection and Detectors
      Unmanned Spacecraft

Distribution Statement : APPROVED FOR PUBLIC RELEASE