Retrieval of near-surface temperature profiles from passive and active optical measurements

Two measurement techniques are used to measure the range and apparent elevation of surface targets. In one set of experiments, a survey station measured the apparent elevation angle, and Global Positioning System data were used to determine the range. In the other experiments, a lidar measured both elevation and range. Two different analysis techniques (one analytical and one involving an optimal estimation model) are used to characterize the shape of the temperature profiles. The six case studies discussed are equally split between stable and unstable cases. In four cases, data from a survey station are analyzed and include measurements of boats, buoys, and a tower. In two cases, lidar measurements of the sea surface were made. Elevation and range data are derived from a nonlinear model of the surface return. For the analytical model, the errors between the derived and the measured range are minimized; typically the range errors are less than 100 m. For the optimal estimation technique, the errors in derived and measured heights are minimized; the height errors are typically less than 1 m. (C) 2002 Society of Photo-Optical Instrumentation Engineers.