Goodland Surveys Pvt Ltd

National Highway Authority of India describes the Land surveying as; The basic objective of the topographic survey would be to capture the essential ground features along the alignment in order to consider improvements and for working out improvements, rehabilitation and upgrading costs. The detailed topographic surveys should normally be taken up after the completion of reconnaissance surveys. The carrying out of topographic surveys will be one of the most important and crucial field tasks under the project. The detailed field surveys shall be carried out using high precision instruments i.e. Total stations. The data from the topographic surveys shall be available in (x, y, z) format for use in a sophisticated digital terrain model (DTM). The Consultants would be fully responsive for any inaccuracy in surveys.

DGPS Surveying, Promark-3 Goodland Surveys Uses 4 unit of DGPS for fixing the ground control points.  The instrument and the adopted methodology gives a perfect accuracy standard, as minimum as 1:25000.  (The mentioned accuracy level is between DGPS and Conventional Total Station Traverse, not just between DGPS Observations). We observe with 4 DGPS units, a base and three rovers (or) 2 base and 2 rovers as explained the picture below. Survey in Static Mode, observation for 50 minutes or more time span according to site + satellite position and post processing are required.  GNSS Solutions is a software for downloading the data and Processing the data.  While processing the data to be checked for a triangle closure, data masking and other errors.  If the processing results are up to the standards then the network to be adjusted and results will be given. Between the DGPS points, with a quality total station to be used for traversing. ...

Using a Total Station CSA News letter about using a Total Station http://www.csanet.org/newsletter/aug94/nl089407.html