GroundWinds Demonstration Campaign Analysis Update MK RAMA VARMA RAJA, CIRA & ORA rama.mundakkara@noaa.gov Jim Yoe, NOAA/NESDIS/ORA James.G.Yoe@noaa.gov
Many Key Demo Campaign Participants University of New Hampshire (UNH) B. Moore, J.Ryan, S.Turco, L.Rosentrater, M.Vosbury, P.Dunphy Michigan Aerospace Corporation (MAC) C. Nardell, P. Hays, K. Moncur, J. Pavlik, M. Dehring Mount Washington Observatory M. Day, K. Rancourt NASA/GSFC B. Gentry, H. Chen NOAA/NESDIS J. Ellickson, R. Mundakkara, J. Pereira, J. Yoe NOAA/OAR M.Hardesty, A. Brewer, B. Rye
Campaign Summary Goals Duration Instrumentation Demonstrate ability to measure LOS winds Demonstrate effectiveness of new technologies Science as “target of opportunity” Duration September 19 – 28, 2000 (Sep 25-28 prime) Instrumentation Three DWL – GW, GLOW, mini-MOPA Locally-launched GPS radiosondes Assorted surface instruments
Campaign Summary (con’d) Operations and Data Collection Subject to FAA restrictions as well as weather Common orientation (AZ/ELEV) for DWL’s Attempted clear/cloudy, calm/active, day/night Data Processing and Posting DWL LOS posted at 1-min, 1-km (or 250m) Analysis Project LOS to LOS Horizontal, average as appropriate Project Radiosonde wind to LOS H
Status as of July 2001 This shows good results for GroundWinds – for higher Photon Count (PC) or brightness values, one would expect a lower standard deviation (STD) in velocity differences. We now realize that “brightness values of GW are most likely photon counts. The reason they are lower is due to misalignment and other problems with the instrument. MAC says that some of the components are of “lesser than expected” quality. Because of misalignment problems, MAC claimed that they were not able to use their patented photon-recycling to process the data to obtain higher counts. Edge1 is the ‘first edge’ of the double edge etalon detector of GLOW.
Status as of July 01 (con’d) Relationship between photon counts and std dev of mean LOS velocity appeared consistent for both GLOW and GroundWinds Same relationship was consistent with model performance for DD DWL GW photon counts lower than expected
Status as of July 2001
Status as of July, 2001 General Agreement between corresponding pairs of wind measurements Lidar-radiosonde differences often large Especially at upper heights Attributable to sampling differences? Other teams had detected DWL retrieval biases, discussed plans to correct them GLOW T dependence, for example GW Correction entailed decoupling Aerosol, molecular retrievals
Spatial Sampling Dependence? Note: GW velocities NOT re-processed
Spatial Sampling Dependence? Re-processed GW velocities
Clear sky, no jet 0.5 – 11 km “Good Signal” Reprocessed GroundWinds
Jet Stream, Clouds 0.5 –10 km Re-processed GroundWinds
Clouds impact wind sensing capability of both GW and GLOW SUMMARY GroundWinds Data re-processing shows improved agreement w/radiosondes when GW signal level is sufficient Clouds impact wind sensing capability of both GW and GLOW Shift in re-processed GW Signal levels needs to be understood (conversion from electrons on detector to photons?)