SailNet Community - View Single Post - Globalstar Failing
View Single Post
post #4 of Old 02-13-2007
Valiente
Senior Member
 
Valiente's Avatar
 
Join Date: Jun 2006
Location: Toronto
Posts: 5,491
Thanks: 0
Thanked 0 Times in 0 Posts
Rep Power: 11
   
Aren't GPS satellites in the same LEO (low earth orbit) as these satcomm birds?

Keep the sextant polished as well!

Edit: I discovered they aren't LEO (http://en.wikipedia.org/wiki/Low_earth_orbit) like some satcomms...they are in the middle range between that and geostationary.

"Orbiting at an altitude of approximately 20,200 kilometers (12,600 miles or 10,900 nautical miles; orbital radius of 26,600 km (16,500 mi or 14,400 NM)), each SV makes two complete orbits each sidereal day, so it passes over the same location on Earth once each day. The orbits are arranged so that at least six satellites are always within line of sight from almost anywhere on Earth.[6]"

from http://en.wikipedia.org/wiki/GPS

That means they are subject to cosmic rays, solar storms, "outages" and whatnot, but aren't likely to be dragged down by atmospheric expansion or other issues affecting LEO birds like Globalstar: http://en.wikipedia.org/wiki/Globalstar

Wikipedia: the sailor's pal.

Last edited by Valiente; 02-15-2007 at 02:16 PM.
Valiente is offline  
Quote Share with Facebook
 
 
For the best viewing experience please update your browser to Google Chrome