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Acoustic Echo Sounding as Related to Air Pollution in Urban Environments

W. R. SimmonsJ. W. WescottFreeman F. Hall

出版	Environmental Research Laboratories, 1971
URL	http://books.google.com.hk/books?id=HY_-1PmJhI4C&hl=&source=gbs_api
EBook	FULL_PUBLIC_DOMAIN

註釋The feasibility of operating an acoustic echo sounder in an urban or industrial environment, without serious degradation in performance and without contributing to noise pollution, is confirmed. Anechoic absorbers placed about the acoustic antenna are the key to improving the sounder performance. Optimum operating frequencies are between 1 and 2 kHz. The design and operation of the all solid state circuitry is described.