Study Of The Technique For Ship Acoustic Correlation Velocity Measurement

Acoustic correlation velocity measurement technology is used to make measurements of velocity relative to the seabed. Acoustic correlation log is a navigation instrument, which is suitable to be equipped on ships, AUV and submarines. It can provide the carrier's moving information and get accurate cumulative sail in real time. Compared to doppler velocity log for the same depth of water, it enables the use of smaller transducer and smaller transmitting power.The major contents in this dissertation are following.1. The developing progresses in the field of ship velocity measurement abroad and domestically are summarized.2. Based on the radial acoustics, general principles of acoustic correlation velocity measurement technology is introduced. Some problems, such as the choice of frequency, estimation of the distance and so on, are discussed according to sonar equation, which should be considered in designing an acoustic correlation log.3. The seabed echo theoretical model for acoustic correlation velocity measurement is founded and some simulation is taken on the temporal correlation and spatial correlation according to this model. The author analyses data acquired from experiment in tank. The result is basically consistent with the simulation.4. The methods using the maximum likelihood and the least square to estimate the unknown parameters are briefly introduced. The theoretical model of the temporal-spatial correlation is deduced in one dimension. The simulation gives a nice result.