RAIL ROUTE ALIGNMENT USING GIS AND GPS

Abstract

Britishers laid out major rail network in India to expand their empire and for better control over the vast land to exploit the resources. This was a boon for Independent India and their coverage was so wide spread that no need was felt for any major railway project after the Independence, except the Konkan Railways. With the increase in population, the pressure is now being felt on the existing rail network and the Indian Railways is planning to append the networks by joining un-served areas. Rail Route alignment involves Reconnaissance survey, Preliminary survey and Final location survey. In conventional method of survey for ground verification or pegging, plane table method is used. Plane table needs reference detail for solving its position and may not be useful in hilly terrains, agricultural areas, or desert areas. In such cases, Astronomical observations are used to find precise position on the ground. Astronomical method's are time consuming and require sound knowledge of astronomy. To overcome these drawbacks, modern techniques such as GIS and GPS are proposed in the present work. GPS (Global Positioning System) gives the accurate absolute position of the occupied point with respect to a universal co-ordinate system (WGS-84) in less time. After the removal of Selective Availability, data captured by a single receiver in point positioning mode has become meaningful. GIS (Geographical Information System) enhances the capabilities of GPS, because of its ability to handle the spatial data and its flexibility to integrate the data from various sources, such as maps, satellite imagery, GPS data etc. The theme of the present work is to develop a methodology using GIS and GPS for ground verification and fixing of the Rail Route on the ground.