A Study Of The Broadband Acoustic Doppler Current Profiling Technique

Broadband Acoustic Doppler Current Profiler (BBADCP) measures the speed and direction of water currents and makes a profile of water current for up to 128 locations. Shipboard configuration can produce profiles of a large mass of water in a short time.Phase coding is one of the main technologies of BBADCP , which transmits long pulses superimposed with a binary pseudo-random code. The echo of water is received and processed to get a profile of current speed at different depths. Small depth cells and high resolution per measuring is the advantage of BBADCP.The main tasks of this thesis are: studying several common Doppler measuring technology used in BBADCP, especially the coded-pulse broadband Doppler method; discussing the frequency evaluating algorithm-complex covariance power spectral moment estimates of correlated pairs (CPPC) and using it to compute Doppler frequency; discussing the designing of the transmitting signal; studying the method of echo processing.As for the frequency estimation methods, this thesis realized the CPPC power spectral moment estimates and proved it to be accurate and reliable.We hope the study would be instructive for the use and realization of BBADCP.