A statistically consistent and physically realistic approach for validating vector magnitude measurements is developed, based on a model for random measurement noise that explicitly satisfies a nonnegativity constraint for all “noisy” vector magnitude measurements. Numerical and analytic approximations are used to quantify the nonlinear functional dependence of sample conditional means...
One year of collocated, rain-free normalized backscatter cross-section measurements from the Tropical Rainfall Mapping Mission (TRMM) precipitation radar (PR) and wind speed estimates from the TRMM Microwave Imager are used to construct fully empirical model functions relating cross section to wind speed for incidence angles from 0° (nadir) to 18°....
Wind measurements by the National Aeronautics and Space Administration (NASA) scatterometer (NSCAT) and the SeaWinds scatterometer on the NASA QuikSCAT satellite are compared with buoy observations to establish that the accuracies of both scatterometers are essentially the same. The scatterometer measurement errors are best characterized in terms of random component...
Sampling patterns and sampling errors from various scatterometer datasets are examined. Four single and two tandem scatterometer mission scenarios are considered. The single scatterometer missions are ERS (with a single, narrow swath), NSCAT and ASCAT (dual swaths), and QuikSCAT (a single, broad swath obtained from the SeaWinds instrument). The two...
Several aspects of feedback mechanisms associated with surf zone sandbar response have been characterized using bathymetric surveys, sampled approximately monthly over a 16-year period at the Army Corps of Engineers' Field Research Facility (North Carolina). The measured bathymetry was alongshore averaged and modeled by the superposition of two Gaussian-shaped sandbars...
Calculation of vector winds from spaceborne fan-beam scatterometers requires that backscatter measurements from different antennas be relatively calibrated to high accuracy. A method is developed to perform postlaunch antenna calibration using global mean ocean backscatter measurements in conjunction with estimates of the statistical distribution of near-surface wind velocity and the...
The European Centre for Medium-Range Weather Forecasts (ECMWF) and Institut Francais Pour la Recherche et l’Exploitation de la Mer European Remote-Sensing Satellite, named IFR2, surface wind velocity data products are compared during July 1995 over the Arabian Sea. Substantial differences were found. The central positions of the maximum isotach were...
Measurements of near-surface winds by the NASA scatterometer (NSCAT) from October 1996 through June 1997 are analyzed to investigate the three major wind jets along the Pacific coast of Central America that blow over the Gulfs of Tehuantepec, Papagayo, and Panama. Each jet is easily identifiable as locally intense offshore...
Ambiguity in wind direction has long been an impediment to applications of wind observations from the Seasat scatterometer (SASS). Three months of unambiguous global SASS vector winds (7 July-10 October 1978) have recently become available from the Goddard Space Flight Center(GSFC) Laboratory for Atmospheric Sciences. The directional ambiguities were removed...
Three months of vector wind observations from the Seasat-A satellite scatterometer (SASS) are used to construct gridded fields of monthly average wind stress and wind stress curl over the global ocean. These fields are examined to identify features either poorly resolved or not present in wind stress fields constructed from...