The basic objective of topographical survey is to determine three dimensional positions of all ground features in the form of x, y and z coordinates with respect to a defined reference system to generate accurate digital terrain model of the project road corridor for preparation of strip plan, designing, working out improvements, rehabilitation, and up-gradation of the project road, design additional facilities, alterations and additions for its development

RSM carries out Topography survey by using total Stations having automatic data recording devices with appropriate feature codes attached to each point. Survey corridor is (20-50) mon either side of the centerline of the existing road.

The information recorded in the Topography survey includes the following:

• Road center line
• Pavement edges
• Outer shoulder edges
• Toe lines of fills and cuts
• Longitudinal and transverse drains/ ditches
• Bridge locations and Details
• Water sources, Ponds etc.
• Culverts with their type and number
• Electric and telephone lines
• Huts, Buildings, fences, stairs, hand pumps, bore wells, wells
• All Buildings were collected with suitable codes depending upon its classification like residential, commercial, educational, health Center, industrial, religious etc.
• All trees with girth greater than 0.3 meters.

Data Processing

All the data from stations and other field records are downloaded regularly on to the field computer and processed with AutoCAD software, to form proper connectivity of linear features based on the feature code and sequence of points collected on the ground. Based on the heights of linear features and spot heights, Digital Elevation Model is generated to check for any holes or voids in the model. The hard copy output of the plan drawing on the suitable scale is taken to the ground by a senior surveyor for physical verification on the ground to check details and for picking up names of the villages and other missing relevant information.