Satellite navigation breakthrough for aircraft and weapons

By Ajai Shukla

Business Standard, 2nd Sept 12

A crucial breakthrough by a small high-technology company drew a personal salute from the Defence R&D Organisation (DRDO) chief, Dr VK Saraswat, in Bangalore today. The SME, Accord Software & Systems, handed over to the DRDO chief a high tech satellite navigation system --- a tiny box, two inches across and a quarter inch high --- that will go into aircraft and tanks, telling them exactly where they are, accurate to 3 metres.

Satellite navigation has been around since the 1990s. The US Pentagon’s Global Positioning System (GPS) is a constellation of some 30 satellites, which tell users their location, altitude and time. The GPS has a commercial signal that is accurate to about 30 metres, which is available to anyone with a GPS receiver. It also has a military signal, accessible only through a secure “precision code,” that is accurate to just one metre. That signal navigates high-precision US weaponry, like the Tomahawk cruise missile, which finds its way across hundreds of kilometers to a particular room in a specified house, flying in through a designated window.

Since the closely guarded GPS “precision code” is available only to the US military, the Indian Space Research Organisation (ISRO) has found a way to improve the commercial signal. Called GAGAN, the acronym for “GPS And Geo-Augmented Navigation”, this uses ISRO satellites to augment the GPS commercial signal, allowing users to determine their position with an accuracy of 3 metres.

Now Accord Software has packed the power of GAGAN into the pint-sized chip that it handed over to the DRDO today. This will power into the navigation systems of indigenous military systems --- including tanks, infantry combat vehicles, aircraft, helicopters, and unmanned aerial vehicles (UAVs) --- that India is developing.

The G3OM, as Accord Software calls its tiny 17-gram module, also harnesses the power of GLONASS, a Russian version of the GPS. The G3OM picks up signals from GPS, GLONASS and GAGAN satellites, integrating all three into an accurate readout. It is built with two antennae so that even when a tank or a UAV is moving, at least one antenna is receiving satellite signals, allowing unbroken navigation signals.

“The G3OM module that Accord developed meets all the specifications that we laid out. It is small, light, rugged enough for military use, and consumes barely any power. Accord has made it to DRDO requirements, but the core technologies are Accord’s,” says Satheesh Reddy, the DRDO scientist who heads its navigation division.

Reddy is confident the G3OM will also be snapped up by ISRO, Hindustan Aeronautics Ltd (HAL), the three services, and will break into selected export markets. He believes private sector companies that are developing systems like the Future Infantry Combat Vehicle, will find the G3OM crucial while developing its land navigation system.

When GAGAN becomes fully operational next year, it will be a boon for civilian airliners over the Indian landmass. Other Space Based Augmentation Systems (SBAS) like GAGAN are functional elsewhere. Over the United States, commercial airliners navigate with the help of a Wide Area Augmentation System (WAAS), developed by the Federal Aviation Administration (FAA), which provides an accuracy of 3 metres. Similar augmentation systems are operational over Europe and Japan. When GAGAN is fully operational it will provide an equivalent system over India.

India has been involved in extended negotiations with Russia for obtaining the “precision code” for its GLONASS system, an alternative to GPS. This would provide Indian weapon systems with the navigational accuracy that US and Russian systems enjoy. But the Russian system has been mired in delay. Russia’s economic crisis in the 1990s prevented that country from launching enough satellites needed for the GLONASS constellation. Only last year, after Prime Minister Putin’s personal push, was the full constellation established.

But Russia remains unwilling to provide India with the “precision code”, although the two countries have signed joint statements about working together on GLONASS. MoD sources tell Business Standard that the matter remains “under discussion”.