[quote=seabreeze_97]I keep seeing statements that it's cheaper to launch satellites than build land-based stations, but never see any references or links to such a cost analysis. Also, how long do the sats last, and how long have the land-based stations been in operation? Typical satellites last about 7-10 years. Ground stations last for decades, and don't require multi-million dollar space shots to upgrade or repair. Did anyone read the linked article on uses for Loran to deliver differential correction for GPS, which the euros have been doing for several years now?
Having GPS is a great by-product of a military investment, but there are no guarantees.
"The initial cost to deploy the NavStar GPS system was 10.5 billion dollars. Annual cost to keep the GPS system running is 400 million dollars. Cost for WAAS is 1 billion, while the cost for LAAS is 300 million.
The cost to operate the LORAN system annually is 28 million dollars. The Coast Guard is planning to invest 109 million dollars in February 2002 which will allow the system to operate through 2008."
Current GPS satellites are lasting up to 15 years. GPS is global, work out how many LORAN stations you would need to get global coverage and then try to get the same accuracy. There is one LORAN tower in Europe experimentally modified to transmit improved LORAN signals, it is not operational and you cannot buy a receiver that can use the signals Ė its experimental. There are already coast guard differential systems and augmentation systems like WAAS, if basic GPS is not good enough.
Successive US presidents have guaranteed GPS continuation to both IMO and ICAO, opening the path for them to formally adopt GPS use.
GPS paid for its development cost in taxes on export receiver sales in its first couple of years of public use. Itís actually a great US export success story that is still generating new jobs around the world.