The Land Based Positional Accuracy Of Gps And Gps Augmented By Gagan Over The Indian Geographical Region

ABSTRACT The Global Positioning System which was commonly known by the North American implementation called GPS the GPS fails to provide an accurate Position Navigation and Time PNT signal over the Indian region. The positional accuracy of GPS is not up to the mark over the Indian region because the India is located near the equator. Moreover the equatorial ionospheric grid point IGP of India differs from the ionospheric grid point of North America so in order to improve the positional accuracy of GPS over Indian region the Indian Space Research Organization along with the Airport Authority of India has launched the space based augmentation satellite called GPS aided and Geo Augmented Navigation satellite GAGAN with PRN number 127 and 128. The GAGAN will make corrections in the ionospheric ephemeris and satellite clock errors in the navigation messages received from the GPS satellites the certification of GAGAN is under progress. The objective of this research is to analyze the positional accuracy of GPS and GPS augmented by GAGAN over the Indian geographical region by using differential correction technique.