Near Intersection of I-35 & I-90 Southern Mn. | Pure no-tiller - 1/8/2012 19:21
now i don't know much about this but, do you add it to WAAS? or is it a whole nother signal?
Yes, it is a whole 'nother signal. It was in existence before WAAS and comes from land based towers. These towers and stations are run by the Government. They were typically placed along water routes and on the Coasts to provide correction for navigation on water. That means that it was/is not available all over the Country.
The basic GPS informatin comes from the satellites orbiting the Earth. The correction information to fine tune your position comes from a land based tower. This means that if you had a combine harvest crew and were moving with the crop that you might need to switch towers as you moved. There could well be areas where you were too far away from aTower and not have any correction at all.
WAAS came along later and is backed by the FAA primarily for Aircraft Navigation. This correction signal is satellite based and covers the majority of the Country. The satellites used appear to be fixed in space like those used for satellite TV/Radio. They get their correction information from ground based stations but deliver it via satellite.
With WAAS, the basic GPS information again comes from the satellites orbiting the Earth. The correction information to fine tune your position comes from anothe satellite rather than a ground based tower. This means that the combine crew mentioned above might move great distances and continue to use the same correction satellite. If they moved completely across the country they might need to use a different WAAS satellite.
Edited by tedbear 1/10/2012 12:27
|
coast gaurd signal
