Method Research Of Dynamic Precise Positioning In Offshore Oil Prospecting

The rapid development of the global economy has led to a sharp increase in the demand for petroleum resources,which has also led to the development of oil prospecting industry,especially the increasingly fierce competition in offshore oil prospecting.And maritime navigation and positioning plays a crucial role.The differential GPS is used for most near offshore prospecting.However,when the prospecting area is over a certain distance from the coast,the accuracy of relative positioning falls sharply.Non-differential Precise-PointPositioning(PPP)technology without reference station,single GPS receiver can realize precise positioning,the static positioning can reach the accuracy of centimeter level,and the global real-time dynamic positioning can reach the decimeter level.The offshore oil exploration with towing streamer as the main mode has short construction period and frequent changing prospecting area,so the global positioning service is needed.Veripos,the Global Satellite Station Differential System,because of its using PPP positioning technology,no distance limit,and global positioning precision can reach 10 ~ 20 cm,become the major means of GPS positioning in the offshore oil exploration.Therefore,this paper based on the PPP technology,and discusses the methods of GPS dynamic positioning of offshore oil exploration,combined with the characteristics of marine navigation positioning and the actual application,from the aspects of accuracy and economic efficiency are analyzedThis article introduces the basic knowledge of GPS.including the composition of the system,positioning principle,method classification and error analysis;The basic theory and algorithm of Precise-Point-Positioning(PPP)are described.Main contents are the IGS products of GPS precise ephemeris and precise satellite clock,the non-differential observation equation and the observation model analysis,processing method of main parameters,data calculating of PPP and analysis of dynamic PPP,etc;This paper focuses on the application of Global Satellite Station Differential System based on PPP technology in offshore oil prospecting,mainly from the Global Satellite Station Differential System working principle,features of offshore oil prospecting,application of Veripos system and accuracy analysis in such as aspects are expounded.In this article,we use the construction data of several offshore oil prospecting projects to analysis and compare the internal and external precision of the navigation and positioning system of offshore prospecting ships.A large number of measured data show that the Veripos system is stable and reliable,The accuracy of both internal and external conformance tests is around 10 cm.and it is almost suitable for global waters.The system has become the main way to locate many offshore oil exploration and other marine scientific research activities.