GPS Surveying

The Global Positioning System is a satellite-based radio navigation system for determination of precise position and time, using radio signals from the satellites, in real-time or in post-processing mode.

1. GEO-TAGGING OF TREES GPS Surveying by Dr. Rambabu Palaka , Associate Professor Civil Engineering Department B.V. RAJU INSTITUTE OF TECHNOLOGY August 2017

2. What is GPS? The Global Positioning System is a satellite-based radio navigation system for determination of precise position and time, using radio signals from the satellites, in real-time or in post-processing mode . The Navigation Satellite Timing and Ranging Global Positioning System (NAVSTAR GPS ) developed by the U.S. Department of Defense ( DoD ) It permits users with suitable receivers to establish their position , speed and time on land, sea or in the air, at any time of the day or night and in any weather condition.

3. GPS System The GPS system has 3 major segments : space, control and user. The Space Segment consists of a constellation of 24 satellites orbiting the earth at an altitude of 20,200 km . These satellites act as reference points from which receivers on the ground determine their position. The Control Segment consists of 5 stations here on earth which track the satellites. The User Segment consists of antennas and receiver-processors.

4. How does GPS work? GPS receivers use the principle of "RANGING". The receiver measures the distance from a location on earth to the positions of several satellites to determine the latitude and longitude of the position on earth.

5. With four satellites you get a precise point for your position and you also know your elevation . You have a position but no check on its quality!

6. Applications of GPS Providing Geodetic Control Photogrammetry - it is the science of making measurements from photographs, especially for recovering the exact positions of surface points Finding out location of offshore drilling Pipe line and power line survey Navigation of civilian ships and planes

7. GNSS ( Global Navigation Satellite System) There are four GNSS systems in existence GPS , GLONASS , Galileo & Compass The Global Positioning System (GPS) is also called NAVSTAR GPS (Navigational System with Time and Ranging )operated by United States Government . The GLObal NAvigation Satellite System ( GLONASS ) operated by the Russian Government. The Galileo Navigation Satellite System to be operated by European Union . The Compass Navigation Satellite System to be operated by Chinese Government .

8. Q&A