September 7, 2017

POINT OF CONTACT

Principle investigator:
     Richard.Eckman
     NOAA Air Resources Laboratory Field Research Division
     1750 Foote Dr.
     Idaho Falls, ID 83402
     Richard.Eckman@noaa.gov
     (208) 526-2740

README.TXT - Description of Data Files for ASC SoDAR (SOD)

Experimental Setup 

A minisodar is a remote sensing device that measures vertical profiles 
of wind speed and direction in the lowest levels of the atmosphere. It 
has a vertical range of as low as 15 m up to 200 m maximum with a height 
resolution of as small as 5 m. The height range and resolution during PSB2 
were set at 30 to 200 m and at 10 m, respectively. One sodar was deployed 
on the tracer dispersion grid during PSB2. 

An Atmospheric Systems Corporation ASC4000 minisodar was located at a 
permanent site designated as SOD at about 800 m arc distance, 57 degrees 
arc angle. Data from the ASC4000 was averaged at 10-min intervals and 
transmitted by radio link back to the ARLFRD office. Computer times on the 
minisodars were regularly checked and synched to the official internet time. 
Power to the ASC4000 was supplied by AC line power.
 
Quality Control

Data was automatically screened for acceptance or rejection by proprietary 
internal algorithms using criteria based primarily on signal-to-noise ratio 
and number of acceptable values during the averaging period. Rejected data 
were specified as missing values. ARLFRD used the software program called 
SodarView for the ASC. The wind speed and direction data sets were plotted 
and reviewed by the data analyst for consistency and accuracy by comparing 
results with other measurements for the duration of each test plus one hour 
before and after each test.  This included the following comparisons:

	All wind speed and direction measurements in the horizontal at 30 m 
	(sonic R6 and cup and vane on GRI, cup and vane on COC), 40 m (cup and 
	vane on GRI), 60 m (sonic R5 and cup and vane on GRI), and 160 m (PRO), 
	where available.

The results for these comparisons are included for each IOP in the Summary 
of Individual IOPs chapter. Most comparisons were good with the exception 
of PRO at 160 m. Data was either sparse or unavailable at one or both of 
PRO and SOD. PRO appeared to sometimes have a low U bias relative to SOD.

Data File Formats

Eight files for the ASC4000 sodar are included in the PSB2 project database, 
one for each of the IOP test days. Each file contains 10-min averages 
covering the 24 h period of the day. The files are designated PSB2_SOD_IOP#.csv 
where # specifies the IOP test number. The times listed are MST (hh:mm:ss) for 
the start time of the 10-min averaging period. The notation in the column headers 
follows: ws = wind speed, wd = wind direction, w = mean vertical wind speed, sdw 
= standard deviation in w, sdu = standard deviation in u, sdv = standard deviation 
in v. Wind speeds and standard deviations are in units of m s-1 and the wind 
direction is in degrees. The number following (30, 40, ., 200) is the height 
of the measurement in meters. Flagged or missing values are designated by 9999 
for wind direction and 99.99 for everything else. The sodar's internal algorithms 
determined which points were missing. No further QC or processing was done.

