SGP 1999 NOAA Wind Profiler Network (NPN) Hourly Radio Acoustic Sounding 
     System (RASS) Dataset

     
     1.0  General Description
     
          The NOAA Wind Profiler Network (NPN) Radio Acoustic Sounding System
     dataset is one of several datasets provided for the Southern Great Plains 
     1999 (SGP99) project.  This dataset contains NPN RASS data from 8 stations 
     in the SGP99 domain.  This dataset covers the complete SGP99 time period 
     (1 July 1999 through 31 July 1999) and domain. The SGP99 domain is 
     approximately 97W to 99W longitude and 34.5N to 37N latitude.  No 
     additional quality control was performed by the University Corporation for 
     Atmospheric Research/Joint Office for Science Support (JOSS).

     2.0  Detailed Data Description
     
          The National Climatic Data Center (NCDC) provides hourly Radio 
     Acoustic Sounding System (RASS) data for the Wind Profiler Demonstration 
     Network (WPDN) on a daily basis in E-BUFR (Enhanced Binary Universal Format
     for the Representation of meteorological data) format.  The RASS measures
     temperature profiles in the lower troposphere.  The RASS sensors 
     work in combination with the wind profiler Doppler radars to produce 
     virtual temperature.  RASS emits an acoustic signal whose propagation
     velocity is measured by the wind profiling radar.  The speed of sound, thus
     measured at each level, is converted to a virtual temperature (similar to 
     the actual temperature except for a small correction dur to water vapor in
     the air).  The accuracy is better than 1 degree C.  The altitude to which
     RASS can measure is limited for two reasons: 1) The stronger the horizontal
     wind, the greater the likelihood that the acoustic will be carried out of 
     the radar beam.  For this reason, many installations place acoustic sources
     at all four corners of the wind profiling radar. 2) The acoustic signal is
     strongly attenuated in air.  RASS measurements with the 404-MHz profilers
     typically extend up to 3-4 kn above ground.  Additional orientation 
     information about wind profiler stations (such as site number, magnetic 
     declination, beam angles, etc.) is read from an accompanying ascii file.  
     A daily netCDF file is produced.

     Currently there are 8 WPDN RASS stations.

     LOCATION                LAT (deg.)  LON (deg.)  ELEV (m)
     ________________________________________________________
 
     Haviland        KS      37.65       99.09       647.7
     Morris(Haskell) OK      35.68       95.86       218.8 
     Platteville     CO      40.18      104.72      1529.3 
     Purcell         OK      34.98       97.52       330.7 
     Vandenberg_AFB  CA      34.76      120.53       149.0 
     Vici            OK      36.07       99.22       647.7 
     White_Sands     NM      32.41      106.35      1224.0 
     Hillsboro       KS      38.31       97.30       446.5   
     Bloomfield      CT      41.89       72.71       184.0 (retired)
 

     2.1  Detailed Format Description

     Observations are an hour average from the preceding hour of data.
     The previous hour's six minute observations are processed to derive 
     an hourly average using a consensus procedure (Barth et al., 1994).  
     The parameters reported/measured:

        magnetic declination (degrees)
        orientation from true N (degrees)
        east beam azimuth angle (degrees)
        east beam elevation angle (degrees)
        north beam azimuth angle (degrees)
        north beam elevation angle (degrees)
        vertical beam azimuth (degrees)
        vertical beam elevation (degrees)
        height above station (meters) 
        RASS quality control indicators (0- Passed all tests; 1- Tests
             not performed; 2- Tests inconclusive; 3- Test B 
             performed and failed; 4- Test A performed and failed) 
        RASS Consensus numbers (0 - 10) (see Barth reference below)
        RASS signal power- 0th moment (dB)
        RASS temperature- 1st moment (degrees Kelvin)
        Profiler in RASS checkout mode - (true/false)
                
                
     Missing Values:

     -99999 denotes missing value
     -9999 denotes station not reporting

     Questions regarding the content of the data stream should be directed to
     Alice Cialella, cialella@bnl.gov, 631-344-3286.

     2.2  Data Remarks
     
          This data is provided "as is".  
     
     3.0  Quality Control Processing
     
          These data were not quality controlled by the University Corporation 
     for Atmospheric Research/Joint Office for Science Support (UCAR/JOSS). 
     
     4.0  References

     ARM, 2000: Release Notice for Wind Profiler Demonstration Network (WPDN) 
     Hourly, November 21, 1996. [Available on-line from http://
     www.xdc.arm.gov/docs/data_info/release_forms/sgp60wpdnrass.release.html]

     Barth, M. F., R. B. Chadwick, and D. W. van de Kamp, 1994.  Data processing
     algorithms used by NOAA's Wind Profiler Demonstration Network, Annales 
     Geophysicae, 12, 512-528.

     Forecast Systems Laboratory (FSL), May 1996, FSL in Review- Fiscal Year 
     1995, U.S.  Department of Commerce, National Oceanic and Atmospheric 
     Research, Boulder, CO, 102 pp.

     National Weather Service and the Office of Oceanic and Atmospheric 
     Research, August 1994, Wind Profiler Assessment Report and Recommendations
     for Future Use 1987-1994, U.S. Department of Commerce, National Oceanic and
     Atmospheric Research, Silver Spring, Maryland, 141 pp. 

     NOAA, 2000: NOAA Profiler Network Data Description. [Available on-line from
     http://www-dd.fsl.noaa.gov/descrip.html]