Record Display for the EPA National Library Catalog


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
Description Access URL
Library Call Number Additional Info Location Last
NTIS  PB97-193775 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 12p
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.