A digital correlative accumulation and its application to underwater acoustic telemetry,telecontrol and remote sensing

A specific digital time correlative accumulation has been developed. It is an adaptable scheme of signal processing for underwater acoustic technology used in telemetry., telecontrol and some remote sensing. Its basic principle is here introduced and the prospects for successful use in an acoustic channel with multipath, time-space variables and high noise level are amply discussed. The performances of this scheme are analysed. The digital time auto-correlative accumulation has been used in two types of acoustic releases, and the cross-correlative accumulation has been used in a shallow water targets telementer. There are some advantageous performances with these devices, for example, the effective range of release can reach about 4 nautical miles in a much complex shallow water area such as that in Xiamen Harbor where the depth ranges from 3 to 30 m, and the targets telemeter can normally keep working in even shallower water area.