GPS

Well, one certainly hopes not. After all, GPS is used by aviators to find their way through the skies, by mariners to thread through dangerous channels and by hikers to ensure they don't get lost amidst the dense underbrush - and let's not forget it's numerous military applications.

Still, the warning signs are visible. Each satellite has a lifespan of around 7.5 years. Several active satellites in the GPS constellation are over a decade old now - significantly exceeding their designed lifespan. These satellites are still functioning (albeit with some on backup systems) - and to be fair, have far exceeded any expectations for useful life. Should the fact that a significant number of GPS satellites are antiques be a cause for concern? In my opinion, no.

There are four distinct generations of GPS satellite - Block 1, Block 2/2A, Block 2R and Block 2F. The current constellation is primarily composed of Block 2/2A satellites, but these are slowly being replaced by the 'next-generation' - Block 2R satellites. Ever since 1997, Boeing Delta 2 expendable launch vehicles have been delivering $40 million GPS 2R satellites into orbit - replacing ageing satellites from the 2A block. This is part of the USAF's 'proactive plan to replace and replenish the GPS constellation.'

Satellites from the 2R generation are significantly superior to their predecessors - they have reprogrammable firmware so that software fixes and upgrades can easily be delivered; they are so advanced that they can perform inter-satellite ranging with other Block 2R satellites to determine their own position!

Looking further into the future, specifically 2006, the first of the Block 2F satellites are due to be launched. These will be the first GPS satellites designed for a lifespan of 12 years and will contain faster processors with more memory. They will also broadcast a new third frequency for civilian use.

In all, I'm pleased to say that the future of GPS is actually looking quite good. The evolutionary increases that each new generation of satellites bring can only aid us civilian users in our never ending quest for greater accuracy

Article Source: http://www.articlesboard.com

Please Rate this Article

5 out of 54 out of 53 out of 52 out of 51 out of 5 

Not yet Rated