Indian Regional Navigational Satellite System
Indian Regional Navigation Satellite System ( IRNSS, German: Indian Regional Navigation Satellite System ) is similar to the existing systems GPS, GLONASS or Galileo under construction a planned Indian system for satellite navigation. All the necessary satellite to be placed into orbit by the year 2014.
History and political aspects
In 2004, was proposed by the Indian Space Agency ISRO its own satellite navigation system to become more independent from the U.S. GPS system. In September 2005, however, an agreement on cooperation was signed on European-led Galileo project. However, the Indian government approved the measures proposed by the ISRO project in May 2006, 14.2 billion Indian rupees ( approximately € 247 million) for the development of IRNSS consisting of seven satellites and a ground unit. In October 2006, India had asked the cooperation and co-financing offered by 300 million euros in the Galileo project for reasons of security aspects into question. Specifically, the possible Chinese access to sensitive was called Indian data. Also on the shared use of the existing Russian GLONASS system was considered, but these do not appear ideal because of the failed satellite and the resulting poorer coverage.
When Indian IRNSS it would not, however, be a global system as the existing systems or Galileo, but to cover India only India itself as well as a 1500 km to 2000 km wide belt. Satellite, earth station and the receiver terminals are to be produced in India, and also to be controlled exclusively by the system in India. The first satellite was launched on 1 July 2013 to its stationary train, the last in 2014.
Three of the seven satellites are geostationary be placed, the remaining four inclined in a geosynchronous also, but at 29 ° to the equatorial plane of the web. All seven satellites will focus as a constant visual contact with the ground station in India. The independently developed satellites will have an accuracy of up to 20 meters. Preliminary figures, there is a weight of the satellite is 1330 kg, and solar panels that can deliver 1440 watts. Whether IRNSS will be compatible with the under construction GAGAN, an Indian satellite-based system to improve the GPS data differential GPS, is not known.
IRNSS consists of two services: the Special Positioning Service (SPS) and the Precision Service (PS). Both services are transmitted in each case in parallel on the L5 frequency ( 1.17645 GHz ), and the S - band at 2.49208 GHz. The SPS signal is transmitted on a subcarrier of 1.023 MHz using binary phase modulation ( BPSK), the PS signal for more accurate position determination using binary offset carrier in the configuration BOC (5,2). The two different transfer methods are used to support the code multiplexing method in order to separate the two broadcast on the same carrier frequency services on the receiver side can.
- ISRO - Industry Meet on Satellite Navigation ( version 4 December 2008 at the Internet Archive )