GPS is becoming ever-more important in our lives, as more smartphones, portable electronic devices, and cars integrate the technology. It's how we harness the power of location - not just for road directions, aviation, and seafaring navigation - but for finding the nearest restaurant, gas station, and much more. GPS and location data are being woven into most forms of social media, as well.
Add the many military uses of GPS (the technology was originally devised for the military and is managed by the Air Force) and you have one very important (and free-to-use) service.
Location technology is so important that many nations have decided that they shouldn't rely solely on GPS as managed by the United States. In the event of a war, or other geo-political confrontation, some nations have decided they want their own global navigation satellite systems (GNSS) in space for their critical civilian and military operations.
That's why there are five satellite navigation systems in place or being developed around the world, including:
- Galileo, being developed by the European Union.
- GLONASS, managed by Russia.
- COMPASS, by the People's Republic of China.
- IRNSS, India.
- QZSS, Japan.
The Galileo system is the most ambitious GPS alternative being developed to date. It was begun (after much deliberation) in 2003, and may be fully operational by 2014. Like the U.S. GPS system, Galileo will have approximately 30 satellites available, and its signals will span the entire globe. The system will cost more than 5 billion Euros to complete. Galileo will be distinguished by a global search-and-rescue feature that will enable each satellite to both receive and send signals back to compatible devices on land or sea. No other GNSS has this feature.
Russia has chosen to go it alone with its GLONASS system. GLONASS was begun in the mid-1970s, and became fully operational, but fell into disrepair. Over the past decade, however, Russia has re-invested in GLONASS, introducing new satellites into the system, and providing signal coverage for much of its region of the earth.
China is developing a constellation of more than 30 satellites, to give its COMPASS GNSS global coverage. COMPASS will have two levels of signals, for civilian and military use. Chinese officials have stated that the COMPASS constellation will be completed by 2015.
India is also hedging its bets in the GNSS game with its Indian Regional Navigation Satellite System (IRNSS). IRNSS is scaled-down, compared to the Chinese, European, and Russian systems. It will include only seven satellites and will cover India and adjacent land and sea. The IRNSS is to be completed by 2014.
Japan's Quasi-Zenith Satellite System (QZSS) takes a different approach. A three-satellite system, expected to be completed in 2013, QZSS satellites orbit over Japan and southeast Asia, and are intended to supplement and increase the accuracy of signals from the U.S. GPS satellites.