Map-making is an inherent cognitive capability of human beings to fulfill their basic needs and desire to explore. This art usually referred to as Cartography, has moved a long way from markings on the trees and cave stones as well as directions through celestial bodies using heuristics to today’s latest applications based on geodesy and web cartography running in real-time. The global satellite based navigation systems, which came into being in 1995 with their full operational capability, revolutionized the parallel developments in the satellite imaging technology. The NAVigation Satellite Timing And Ranging Global Positioning System (NAVSTAR GPS) from the United States of America and the Globalnaya navigatsionnaya sputnikovaya sistema (GLObal NAvigation Satellite System, GLONASS) from RUSSIA aided their military users and on availability to the cartographic community changed the way of surveying and mapping in different countries. The photogrammetric processing required for cartography purposes, topographic mapping, and photogrammetric product generation need high accuracy in both horizontal (planimetric) and vertical directions. The presented study covers various experimental sites in India at Dehradun site, Uttarakhand; Jaipur site, Rajasthan; Kendrapara site, Odisha; Chandigarh site, and Delhi site where the Differential GPS (DGPS) surveys in the static mode were carried out using Leica 500 series GPS, Trimble Net R9, and Trimble R7 Global Navigation Satellite System (GNSS) geodetic receivers. The horizontal and vertical precisions achieved in the post-processing of these collected GPS survey datasets using DGPS / DGNSS mode range from 2mm - 6mm majorly. The root mean square error (RMSE) attained for the satellite triangulation is better than a pixel resulting in the photogrammetric generation of significantly more accurate digital elevation models (DEM) as compared to the DEMs based on rational polynomial coefficients (RPC) alone and further improved orthoimages for the study sites using Cartosat-1 stereo pairs.
Overall, it is very valueable research work.