The Optical Autocovariance Wind Lidar. Part II: Green OAWL (GrOAWL) Airborne Performance and Validation

Details

• Journal Title:
  Journal of Atmospheric and Oceanic Technology
• Personal Author:
  Baidar, S. ; Tucker, S. C. ; Beaubien, M. ; Hardesty, R. M.
• NOAA Program & Office:
  OAR (Oceanic and Atmospheric Research) ; ESRL (Earth System Research Laboratory) ; CSL (Chemical Sciences Laboratory) ; CIRES (Cooperative Institute for Research in Environmental Sciences)
• Description:
  A two-look airborne Doppler wind lidar operating at the 532-nm laser wavelength, the Green Optical Autocovariance Wind Lidar (GrOAWL), was built and flown aboard the NASA WB-57 research aircraft. Flight campaign goals were to validate the instrument wind measurements and to demonstrate the two-look measurement concept proposed for spaceborne mission concepts such as the Atmospheric Transport, Hurricanes, and Extratropical Numerical Weather Prediction with the Optical Autocovariance Wind Lidar (ATHENA-OAWL) mission. The GrOAWL-measured winds were compared with collocated dropsonde measurements. Line-of-sight velocity (LOSV) measurements for the individual GrOAWL looks showed excellent agreement with dropsondes (R-2 > 0.9). The LOSV biases were very small and not statistically different from 0 m s(-1) at the 95% confidence interval (-0.07 +/- 0.07 m s(-1) and 0.01 +/- 0.07 m s(-1) for look 1 and look 2, respectively). The wind speed and direction profiles retrieved by combining the two GrOAWL looks were also in very good agreement (R-2 > 0.85). An instrument performance model indicated the instrument wind measurement precision was likely lowered (uncertainty was increased) by a factor of similar to 3.3 during the flights relative to predicted as built instrument performance. The reduced performance was not observed during ground-based atmospheric testing and thus has been attributed to impacts of the harsh operating conditions of the WB-57 aircraft (high vibration, thermal gradients, and high humidity). The exercise of scaling the GrOAWL instrument performance and grid scale to space showed space-based OAWL wind measurements would yield products with precision at least as good as the GrOAWL instrument.
• Source:
  Journal of Atmospheric and Oceanic Technology, 35(10), 2099-2116.
• DOI:
  http://dx.doi.org/10.1175/jtech-d-18-0025.1
• Document Type:
  Journal Article
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha256:6b5bf1d0a2a2476364647d8fc90c8a23adbde2ed75e24f452f6b89a707033fad
• Download URL:
  https://repository.library.noaa.gov/view/noaa/21474/noaa_21474_DS1.pdf
• File Type:
  [PDF - 2.51 MB ]