Edge Technique Lidar for High Accuracy, High Spatial Resolution Wind Measurementin the Planetary Boundary Layer

摘要

The goal of the Army Research Office Geosciences program is to measure the threedimensional wind field in the planetary boundary layer (PBL) over a measurement volume with a 5O meter spatial resolution and with measurement accuracies of the order of 20 cm/sec. The objective of this work is to develop and evaluate a high vertical resolution lidar experiment using the edge technique for high accuracy measurement of the atmospheric wind field to meet the ARO requirements. In the edge technique, a laser is located on the steep slope of a high resolution spectral filter. This produces large changes in measured signal for small Doppler shifts. A differential frequency technique renders the Doppler shift measurement insensitive to both laser and filter frequency jitter and drift. The measurement is also relatively insensitive to the laser spectral width for widths less than the width of the edge filter.