Title Simple LADCP data processing method with bottom tracking
Authers Tsutomu SAITO
Keywords LADCP, data processing, accuracy evaluation
Citation Bull. Fish. Res. Agen. supplement No. 23,1-9,2008
In LADCP (Lowered Acoustic Doppler Current Profiler)observations an unique data processing of following procedures is examined. First, every relative velocity profile obtained with a fixed time interval in a down cast is transformed into an absolute velocity profile by adding the horizontal ADCP drift velocity at each time. Next, they are averaged for every depth and consequently a full absolute velocity profile is obtained. Here, the horizontal ADCP drift velocity at each time is estimated from the mean difference between the relative velocity profile at the time and the absolute velocity profiles at the adjoining times. For a starting point of the chain of process, absolute velocity profiles obtained by ADCP bottom tracking near a sea bottom are used. For accuracy evaluation, rms differences between the LADCP data and vessel-mounted ADCP data obtained in five observations are calculated. As a result, the rms differences classified by depth layer (36-500 m)and by observation are about 15 cm/sec in common.
URI http://www.fra.affrc.go.jp/bulletin/bull/bull23/saito.pdf