Vehicle-borne Highway Geometric Alignments and Facilities Data Capture Using DGPS and GPS/GIS Integration

摘要

In this paper, the author demonstrates how real-time Dif-ferentialrnGPS (DGPS) could be used for highway geomet-ricrnalignments and facilities positioning. The basic con-figurationrnfor a highway data capture system is illustrated.rnSince GPS could supply large, high accuracy, “fresh”,rncost-effective and timely spatial data, it is gradually be-comingrnone of the main data capture and update methodsrnfor GIS-T. When GPS are adopted for the location posi-tioningrnto highway geometric alignments and facilities,rnthe results is usually a series of discrete coordinates inrnWGS 84. The highway agencies often use continuouslyrnexpressed mileage (spatial) to match with a vast variety ofrndistance-distributed highways attributes. To realise therncorrect information match, there is need to establish arnhigh accurate linear reference system (LRS). This is thernprecondition and also the starting point in using the inte-gratedrnGPS/GIS to solve the land surface transportationrnproblems (A. Vonderohe; K. J. Dueker and R. Vrana,rn1992; R. W. Stokes and G. Marucci, 1995). Conventionalrnstraight line-based distance calculation algorithm in LRSrnis by definition inaccurate on curvilinear segments, whichrnis the domain technology when dynamic segmentation isrnused for data retrieval or visual display. In this paper, arnsimple and practical data model for highway characteris-ticrnfeature identification, 2D (3D) coordinates to 1D mile-agerntransformation, curvilinear length calculation is pre-sented.rnSome mathematic formulas are developed. Otherrnfoci of this paper are on the exploitation of the potentialrnusage for the collected GPS data. Based on the above methodologies and as a prototype of integrated GPS/GISrnapplications, a highway geometric alignment and facilityrninformation system is developed for an about 13-km ele-vatedrnurban road in Shanghai, China.