Polar satellite coverage

[Kimberly]

I want to provide the poles of Kerbin with continuous coverage of Figaro GPS satellites, in addition to the rest of the planet of course. What orbits/how many satellites will I need? My current plan is to use highly eccentric orbits at a 90-degree inclination, so satellites will spend most of their time above one pole, and to use two satellites per orbit (180 degrees apart). I'm bad at visualizing it, though...will that suffice?

Edited June 26, 2013 by Kimberly

[capi3101]

If you want to do it like a true GPS system, you'll probably want four satellites in the orbit (each 90 degrees apart from one another) and you'll want the orbit to be circular. The actual GPS constellation has six such orbital lanes at 55 degrees inclination separated by 60 degrees of right ascension, 24 satellites total (at least, that was prior to 2012; the new system has 32 satellites.

One such orbit will probably suffice for your purposes.

[maltesh]

To get continuous coverage over a spherical surface, including both poles, with only four satellites, you can use John Draim's Tetrahedral Satellite Configuration.. It uses four satellites arrayed in four separate elliptical orbits (eccentricity =0.28), inlcined at 33° and arrayed so that they maintain a tetrahedral framework around the planet.

But that's really more of a commsat setup than a GPS setup. My signature contains a challenge that involves setting up such a configuration over Kerbin.