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Old 11-12-2007, 05:23 PM   #23
offroute
Gnarly Adventurer
 
Joined: Nov 2005
Location: Truckee/Tahoe
Oddometer: 357
Quote:
Originally Posted by TomW
Yep, based on what I learned he's right about that, and so are you. I learned from my bro that their satellites are not in true polar orbits (where the satellites wouldn't favor a specific location on the earth). They're in orbits inclined at 52 degrees to the equator, meaning they won't go north of 52 degrees north latitude (or 52 degrees south latitude). Also meaning that at any given time, for those of us in the northern mid-latitudes, more satellites are likely to be south of us than north of us. Some may be overhead or north of us (as long as we're south of N52 deg), but it's slightly more likely that they'll be to the south. I don't know how significant the theoretical latitude factor is, but your informal test to date seems to bear out the generalization.

GlobalStar is having some tech issues with their satellites and from what I gather, they're pushing data applications over voice until they get their second generation birds up starting in 2009.

Interesting factoid my brother picked up: the competing sat phone system (Iridium) was planned for a constellation of 66 satellites and 11 orbiting spares for a total of 77 in polar orbits. The atomic number of iridium is 77.

I think GlobalStar looked at population distribution and decided that most people lived between N52 and S52, so a smaller number of satellites (40) could satisfactorily cover that area from inclined orbits. Clever.

Cheers.
Interesting info TowW. Thanks!

I've used GlobalStar sat phones in central Idaho a few different times. I was constantly having to climb up different sides of the Middle Fork Salmon canyon walls to be able to use the thing. It was pretty frustrating. My experience with the SPOT device here in the Tahoe area is certainly much better than that.
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