Ocean bottom control using the global positioning system

Abstract

One of the most fundamental challenges of working in the ocean environment is the establishment of a geodetic control system, similar to the more familiar geodetic networks on the earth's land areas. Applications of ocean bottom control network, which are well-identified by the marine community, are numerous. The NAVSTAR constellation of the Global Positioning System (GPS) provides a unique capability. The expected visibility of its four to seven satellites anywhere anytime on the earth's surface will enable instantaneous real-time positioning of a buoy, thus eliminating complex mathematical modeling of its motion. This buoy can simultaneously be triggered to measure ranges to a network of ocean bottom transponders through acoustic link, thus replacing the conventional expensive use of a ship. The concept takes advantage of a double pyramid formed between GPS satellites and the transponders linked via buoy. The measured ranges, solved in the geometric mode through the least squares method, will thus provide geodetic positions of transponders.