TITLE:  Profiler/Sodar ABLE Sodar Wind Profiles [ABLE] 


Richard L. Coulter - ER 203
Argonne National Laboratory
9700 South Cass Avenue
Argonne, IL 60439

Voice: 630 252-5833
Fax: 630 252-5498
Email: rl_coulter@anl.gov


This data set contains hourly profiles of wind speed and direction from
the the Atmospheric Boundary Layer Experiments (ABLE) Doppler Minisodars
operated by the Argonne National Laboratory in the Walnut River Watershed
in Butler County Kansas (east of Wichita).  During the IHOP period three
sodars were in operation.  Data cover the period from 13 May to 25 June 
2002 The data are in ASCII format.


2.1  Instrumentation

The ABLE minisodar : One of these instruments is placed alongside each of
the RASS wind profilers. 

General Purpose 

The minisodar measures wind profiles from about 10 m to 200 m above the 
surface, thus filling in the gap left below the minimum height of the wind 

Primary Quantities Measured 

The primary quantities measured the the system are the intensity and Doppler 
shift of backscattered acoustic energy from index of refraction fluctuations 
(created by temperature and wind fluctuations) embedded in the atmosphere. 

Detailed Description 

List of Components 

The minisodar has been developed and fabricated at Argonne National Laboratory
(ANL). It consists of a 32 element array of piezoceramic tweeters mounted 
vertically within a protective enclosure roughly 1.5 m X 1.5 m X 1.5 m. The 
acoustic "in phase" transmission is reflected off a plate into a vertically 
propagating wave. This orientation enables the system to operate in all
weather conditions. 

The minisodars operate by transmitting in two different vertical planes and 
receiving backscattered energy from refractive index fluctuations moving with 
the mean wind. By sampling in the vertical direction and two tilted planes, 
the three components of motion can be determined.

The system consists of a single phased array antenna that transmits alternately 
along three pointing directions: one vertical, one in the north-south vertical 
plane (to the north) and one in the east-west vertical plane (to the east). 
The non-vertical beams are tilted about 17 degrees from vertical. 

Radial components of motion above each pointing direction are determined 
sequentially, separated by about 1.5 seconds. Thus the system repeats its 
sequence about every 5 seconds. The data from each transmit pulse are processed 
with a FFT centered about each range gate (e.g. every 5 m increment in the 
vertical) to determine the mean Doppler shift. The signal-to-noise ratio is 
used to determine if each estimate is acceptable. All the acceptable data 
within an averaging interval (e.g. 15 minutes) are averaged and combined to 
produce a wind profile if there are enough acceptable data points (25%, e.g.) 
within the interval. 

The averaged data are output in files with format similar to radar wind 
profiler (".sod") format for consistency. High resolution radial moments 
data and spectra can be produced if desired. 

2.2  Station Locations

                  UTM km (Zone 14)
Site              99 deg Meridan       DEG     dddmmmsss  ddmm.mm   Alt (m)
Beaumont, KS      4167.1 UTMN km       37.627  37 37' 38" 37 37.64'  478
                   717.2 UTME km       96.538  96 32' 19" 96 32.32'

Oxford, KS        4126.7 UTMN km       37.273  37 16' 25" 37 16.41'  360
                   668.8 UTME km       97.095  97 05' 45" 97 05.75'

Whitewater, KS    4189.5 UTMN km       37.841  37 50' 26" 37 51.43'  416
                   659.6 UTME km       97.186  97 11' 10" 97 11.16'

For file names the station IDs are as follows:

Beaumont   be
Oxford     ox
Whitewater wh

Topo maps and aerial photos are available at:


UCAR/JOSS conducted no processing or quality control on these data.


4.1  Data Format

These data are in ASCII format.

Note:  The sodar wind profile data files
have been converted from their orginal
format to the pop4 format of the 915 MHz
wind profiler data.  In doing so some of
the header values are only place holders.

Line     Description
----     -----------

1        Instrument
2        Parameter measured
3        N. Lat.
         W. Long.
         Site elevation (m)
4        End date and time of data collection UTC
5        Averaging time (sec)
         Number of beams
         Number of range gates
6        Samples required for consensus:Total samples (placeholder) (pair for each beam) 
7        Null placeholders
8        placeholder
         Vertical correction for oblique beams (0=N, 1=Y)
         Number of range gates (oblique and vertical)
         Spacing between range gates (m) (oblique and vertical)
9        Azimuth and elevation (pair for each beam)
10       Data columns header
11-      Range gate height AGL (km)
         Wind Speed ( /s)
         Wind Direction (deg)
         Radial Velocity (vertical and oblique)
         Percent of samples returned (vertical and oblique)
         Mean SNR (dB) (vertical and oblique)
End      $-EOF flag

All times are UTC.

4.2  File Naming conventions

        wh is the station ID (here Whitewater)
        02 is the year (2002)
        06 is the month (June)
        08 is the day of the month




ABLE Home Page: gonzalo.er.anl.gov/ABLE/index.html