Sound speed variations in the Arabian Gulf and their effect on multibeam echo sounding
The objective of this project is to study the effect of sound and speed variation on multibeam echosounders using real field data from the anomalous operating environment of the Arabian Gulf. The data were collected on the Saudi Aramco concession area between 1991 and 1995. Algorithms for the speed of sound in seawater are compared. The updated version of the Chen and Millero formula is recommended for use in areas with salinities of up to 65% and temperatures up to 40 °C. Variability of the salinity, temperature, and sound speed within the Gulf is assessed and described. The temporal and spatial variations of sound speed in the water column are studied and recommendations for certain sampling procedures to be followed are given. Those recommendations include the continuation of usage of the current CTD probe to measure sound speed profiles (SSPs) thrice a day, the usage of a pressure sensor to measure the transducer depth accurately, and the creation of a database for the SSPs with a coordinated position of each cast.