Comparison of Metek Phase Doppler SODAR 64 and 1290 MHz RASS with Tower instruments in the
LINEX2000 experiment at Lindenberg
Meteorological Observatory
General
Within the frame of the data quality assurance for participating systems in the
LINEX2000 experiment a comparison of the phase array SODAR 64 and the 1290MHz RASS
extension with a mast instrumentation were performed for a 4 day period in 2 heights.
Data Retrieval
600s averages of the mast and 1800 s averages of the SODAR/RASS were collected.
The heights of the mast are given by the requirements of the data acquisition used for the
synoptic models of DWD. Therefore, the height of the mast base above sea level (asl) must
be considered. In order to match the heights of the SODAR data and the heights of the mast
data at 57 m and 98 m above ground level (agl) synthetic height profiles were determined
for the SODAR data.
Shown Samples
The samples show the SODAR/RASS averages (1800 s) and the corresponding mast
averages (600 s) which are closest in time to the SODAR/RASS averages. which are measured
inside a volume of typical dimensions of 20 m x 20 m According to the types of the
measuring sensors and the different statistical scatter of the measuring variables the
deviations for the temperature and wind direction appear smaller than for the wind speed.
The regression parameters for 57 m are:
|
Wind Speed [m/s] |
Wind Direction [°] |
Temperature[°C] |
| Correlation |
0.96 |
0.98 |
0.98 |
| Slope |
0.97 |
1.01 |
1.00 |
| Bias |
0.26 |
5.89 |
-0.18 |
Main SODAR Operation Parameters
| Ave |
= |
1800 |
Averaging Interval 1800 s |
| Trans |
= |
2000 |
Acoustic Frequency 2000 Hz |
| Step |
= |
20 |
Height Steps 20 m |
| Hmin |
= |
40 |
Start of Sampling 40 m |
Sample Data
The following examples shown wind speed, wind direction and virtual temperature data
taken at a height of 98 m.
click image to expand |
Wind Speed |
click image to expand |
Wind direction
|
click image to expand |
Virtual Temperature |
E&OE
Thank you for visiting www.biral.com/met/sodar/sodarapp4.htm |
