ABSTRACT
The Global Positioning System is also known as ‘Navstar’ and is operated by the United States Department of Defense. Galileo is a joint European Commission and European Space Agency initiative to provide a non-military global satellite position-fixing system with an expected accuracy of a few metres for the Open Service. The Indian Regional Navigation Satellite System is currently under construction by the Indian Space Research Organisation. Loran-C is a pulsed hyperbolic position fixing system operating at 100 kHz. New global navigation satellite systems are being introduced and an updated long-range navigation system known as ‘e-Loran’ is being introduced to complement the satellite systems. The Russian Global Navigation Satellite System became fully operational in 2010 and comprises a space sector consisting of 24 operational satellites at altitudes of around 19,100 km. A receiver capable of receiving both systems takes advantage of the best features of each individual system.
