Recent progress in 2-component wind field observations by the REAL and motion estimation algorithms

This presentation will report on recent advances in observing two-component vector wind fields in the lower atmospheric boundary layer using a single high-power eye-safe rapid-scanning elastic backscatter lidar and motion estimation algorithms. In 2013, we operated the Raman-shifted Eye-safe Aerosol Lidar (REAL) and a compact Doppler lidar nearly continuously for over 7-months in Chico, California, in an effort to validate the vector wind fields produced from the REAL and two motion estimation algorithms. (The Doppler lidar was used to validate the wind vectors from the REAL.) One algorithm uses a traditional cross-correlation method. The second algorithm, wavelet-based optical flow, is entirely new and appears to offer higher spatial resolution flow fields when compared to the traditional cross-correlation method. The field experiment had two phases. During phase one, we operated the Doppler lidar at 1.5 km range from the REAL. This enabled us to compare time-series of wind components where the conic scan of the Doppler lidar intersected the PPI scan of the REAL. Time-series comparisons were conducted for 50, 100, and 150 m AGL. During the second phase, we placed the Doppler lidar on the roof of the REAL container (see Figure) and either scanned both systems horizontally, or held the Doppler beam fixed horizontally while the REAL performed PPI scans through it. In this way, we are able to make spatial comparisons of the wind measurements. The experiment ended on 15 January 2014 and the processing and analysis of over 5 TB of data is being conducted at the time of this writing. In addition to showing time lapse visualizations of 2-component boundary layer air flows, we will also show time and space series comparisons, and statistical results in order to evaluate the quality and reliability of this emerging wind field measurement technique.