Abstract:
The discharge measurement in river is the basis for using of water, planning, designing and operating water
management and development projects. The traditional method of measuring the discharge is based on measurement
of the water velocity and cross section area. Current meters are commonly used to determine of water velocity but
they require calibration at frequent intervals in laboratory flumes to get accurate results. Because cup and propeller
equipments of current meters may be physically damaged, especially river conditions. Recently, acoustics
velocimeters are increasingly used with the advances in remote sensing and data processing techniques. There are
currently several manufacturers of commercial acoustic devices but the general principles of operation are based on
the Doppler shift effect which is the difference in frequency (shift) between transmitted pulses and received echoes
in water. Acoustics velocimeters provide accurate and economical discharge measurements with simple and fast
operation under different flow conditions. The purpose of this paper is to present principles of operation of acoustic
Doppler velocimeters with results of field and open channel discharge measurements.
