Topographic survey and resource mapping using GNSS

Abstract

A topographic map is a detailed and accurate two-dimensional representation of natural and human-made features on the Earth's surface. For an agriculture engineer, it is an important prerequisite as their sphere of activities include soil and water conservation, design and execution of irrigation systems, drainage network, location decisions of farm infrastructures, local and regional agricultural planning among other things. This project work mainly focused on the preparation of topographic map of KCAET campus, Tavanur using modern surveying equipments such as DGPS (Trimble) and Total Station (Pentax). Using the field collected data from DGPS, a topographic map was plotted using ArcGIS10.3 software. TIN, contour map were generated from this topographic map. In GNSS survey, post- process kinematic survey method was adopted. Post- processing of field collected data was done in Trimble Business Center software. The base line report obtained by exporting the data from the software provides the longitude, latitude, elevation, easting and northing etc. of the field point. It was found that, in Kerala terrain (with dense canopy) working with DGPS alone does not give good result whereas, in combination with TSS gives better and more satisfactory results. The integrated survey using DGPS and TS gives more accuracy and great speed in topographic surveying and they can be used to accommodate various engineering planning requirements. GNSS and TS are not replaceable equipments but, they are complimentary to each other.