THE DEGRADATION OF DOPPLER SODAR PERFORMANCE DUE TO NOISE - A REVIEW

Ambient background noise is a common problem for poor Doppler sodar pe rformance. This noise can be active or passive and broad-band or narro w-band. Active broad-band noise decreases the sounding range of the so dar 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 soda r with zero Doppler shift. Use of acoustic shielding is discussed as a method of noise pollution control by isolating the side lobe energy o f the transmitted acoustic pulse. At the same time, these acoustic shi elds are effective in blocking out active ambient background noise. Pr evious studies which experienced noise interference are shown as examp les of problems that are frequently encountered. Published by Elsevier Science Ltd.