Main Title |
Degradation of Doppler Sodar Performance Due to Noise. |
Author |
Crescenti, G. H. ;
|
CORP Author |
Environmental Protection Agency, Research Triangle Park, NC. National Exposure Research Lab. |
Publisher |
1997 |
Year Published |
1997 |
Report Number |
EPA/600/A-97/034; |
Stock Number |
PB97-193775 |
Additional Subjects |
Sodar ;
Doppler radar ;
Background noise ;
Signal to noise ratio ;
Remote sensors ;
Radar equipment ;
Air pollution monitors ;
Planetary boundary layers ;
Noise sources ;
Wind velocity ;
Wind profiles ;
Acoustic pulses ;
Doppler shift ;
Signal interference ;
Acoustic shielding ;
Narrowband ;
Broadband ;
|
Internet Access |
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB97-193775 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
12p |
Abstract |
Ambient background noise is a common problem for poor Doppler sodar performance. This noise can be active or passive and broad-band or narrow-band. Active broad-band noise decreases the sounding range of the sodar by decreasing the signal-to-noise ratio. Active narrow-band noise can be interpreted as erroneous wind values. Passive noise sources are objects which reflect the transmitted acoustic pulse back to the sodar with zero Doppler shift. Use of acoustic shielding is discussed as a method of noise pollution control by isolating the sidelobe energy of the transmitted acoustic pulse. At the same time, the same acoustic shields are effective in blocking out active ambient background noise. Previous studies which experienced noise interference are shown as examples of problems that are frequently encountered. |