Research On The Features Of Underwater Acoustic Channel Based On Acoustic Ray Theory

Sound wave is the most important information carrier in the sea, and the features of underwater acoustic channel plays very important role for the signal transmission through long distance. This paper deals with the researches on the features of underwater acoustic channel using theoretical analysis and computer simulation.The main contents and contributions of this dissertation are as follows: 1. Several underwater acoustic channel models are investigated, the emphases isplaced on the features of acoustic ray theory model and on its feasibility inpractical use for real sea environments. 2. Studied the transmission loss due to sea surface refraction and sea floor refraction,and the underwater acoustic channel with assumption of uniform horizontaldistribution of sound profile, then, as a result, obtained the eigenray searchingalgorithm, transmission loss through shallow sea and deep sea channel andchannel impulsive response. Comparing with Kraken model shows that the resultsare correct. 3. Studied the acoustic propagation through the sea area with wedged sea floor,proposed the algorithm for acoustic ray tracking, acoustic intensity calculation andeigenray searching and then completed an acoustic field prediction software andthe field simulation. 4. Based on real underwater acoustic channel features, a new method on channelmeasure is presented, which can be applied to compute the multi-path signalamplitudes and their time delays through acoustic channel using spectrum andnonlinear least square estimations.The results and research methods of this paper will have wide applications for underwater digital communications.