ISRO, Raytheon complete tests for GAGAN Satellite Navigational System | India Defence ISRO, Raytheon complete tests for GAGAN Satellite Navigational System Farnborough: An ambitious satellite-based navigation system being developed by India's space agency ISRO and US defence major Raytheon has successfully completed preliminary tests, a top official of the American company announced said. The preliminary system acceptance test for the Technology Demonstration System (TDS) of the GPS-aided Geo Augmented Navigation (Gagan), being developed by the Indian Space Research Organisation (ISRO) to improve Air Traffic Control, was successful, Raytheon Vice President Andy Zogg told reporters here. "This test was significant because the Gagan-TDS ground elements supplied by Raytheon were installed and integrated ahead of schedule," he said. "More importantly, the system functioned properly and exceeded the accuracy requirements." The Airports Authority of India (AAI) plans to use Gagan to meet the civil aviation industry's growing needs in communications, navigation and surveillance and air traffic management. It will result in greater efficiency and safety in over 100 airports in India. The Gagan-TDS network monitors Global Positioning Satellite (GPS) signals for errors and then generates correction messages to improve accuracy for users. Once in place, the system can also be used by other modes of transport, including rail, road and maritime traffic. During the test period, average accuracy of Gagan-TDS was better than one metre horizontally and only slightly more than one metre vertically, thus surpassing the 7.6 metre requirement by a significant margin. "We are very pleased with the cooperative effort among Raytheon, ISRO and AAI that led to this successful test," said Zogg. "The TDS phase of this programme demonstrated how to successfully deploy a SBAS (Satellite-Based Augmentation System) in India, so all of the participants are better prepared for the next stage of the programme." ISRO awarded a contract in November 2004 to Raytheon to supply and install the ground-based elements of Gagan. India is investing nearly Rs 110 crore in the project. The Gagan-TDS is the first phase of the project sponsored by ISRO and AAI to implement a space-based navigation system in Indian airspace. Gagan is one of several systems being deployed around the world as part of an initiative endorsed by the International Civil Aviation Organisation to help civil aircraft move to satellite-based signals from ground-based navigation aids. The technology enhances navigation in all phases of flight, from take-off through landing. Routes are more flexible and efficient, landing safety is increased, and navigation service providers offer better guidance at lower costs. The Gagan-TDS project consists of an Indian Monitor and Control Centre in Bangalore, an Indian land uplink station also in Bangalore, and eight reference stations distributed across the country. Raytheon supplied the sub-systems, installed the units in partnership with ISRO and AAI and then integrated the system through data links provided by the Indian agencies. With the completion of the preliminary system acceptance test, Raytheon will work with ISRO to integrate the ground elements to a geo-synchronous satellite. After integration, a signal-in-space broadcast of Gagan-TDS messages will be demonstrated. Raytheon, which clocked sales of $ 21.9 billion in 2005, is a leader in defence electronics, space, Information Technology and special mission aircraft.