Use of GPS (Global Positioning System) for Dynamic Positioning of Hydrographic Survey Platforms

摘要

The Navstar Global Positioning System (GPS) is a satellite-based radio navigation system designed to provide continuous all-weather navigation to appropriately equipped users on a worldwide basis. The NAVSTAR system of navigation satellites may be exploited in several ways to support dynamic positioning of hydrographic survey platforms. Range observations from four satellites provide direct positioning in the World Geodetic system 1984 (WGS 84) terrestrial coordinate frame with an accuracy from 16 meters for the Precise Positioning Service (dual-frequency ranging) to 76 meters for the Standard Positioning Service (single-frequency ranging), spherical error probable. Higher precision is obtainable, especially for near-shore survey applications, using simultaneously measured phase observations acquired at sea and at land-based control points. With this method of positioning, the dynamic path of the survey vessel may be obtained with accuracies better than 1 meter. In addition to these applications, GPS may be used to determine survey vessel attitude and to establish undersea acoustic transponder control. This paper presents a synopsis of actual and anticipated results for each of these hydrographic surveying applications.