Free Republic
Browse · Search
General/Chat
Topics · Post Article

To: Squawk 8888
Nope- a stable orbit without thrusters must be focused on the centre of the earth, so geosynchronous orbits are only possible over the equator. Satellites that orbit above or below the equator actually cross the equator at an angle twice during each orbit; the angle at which it crosses will be the same as the maximum north and south lattitude over which it will orbit.

Pardon, but a slight quibble with the terminology. An inclined orbit at geosynchronous altitude is still geosynchronous (although noone would call it "geostationary"). From a fixed point on the earth, as you imply, the satellite appears to wander north and south of the equatorial plane. Throw in a slight eccentricity in the orbit, and the north-south deviation becomes a figure eight.

TV stations, along with other geosync satellite users, have to use dishes that are dynamically steered through small angles in alt/azimuth (larger than their beamwidth) to track these satellites.

A friend who had to install a number of ground stations was told by the satellite people that it cost the satellite less station-keeping fuel to have an orbit like that, implying a longer satellite life.

35 posted on 07/26/2010 9:56:19 PM PDT by Erasmus (Personal goal: Have a bigger carbon footprint than Tony Robbins.)
[ Post Reply | Private Reply | To 32 | View Replies ]


To: Erasmus

bookmark


36 posted on 07/27/2010 12:18:47 AM PDT by Publius6961 ("In 1964 the War on Poverty Began --- Poverty won.")
[ Post Reply | Private Reply | To 35 | View Replies ]

Free Republic
Browse · Search
General/Chat
Topics · Post Article


FreeRepublic, LLC, PO BOX 9771, FRESNO, CA 93794
FreeRepublic.com is powered by software copyright 2000-2008 John Robinson