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To: sonofstrangelove

I’m not sure that this guy knows that much about geosynchronous satellites and jamming.

Uplinks to these birds can be from a small spot beam footprint. A 1watt signal sent up to the bird from inside this area will reach it. To jam this uplink you must also be inside the spot beam footprint. So if the spot beam was centered on Langley you would need to be nearby to interfere.

The downlinks can also be spot beamed to a smaller area. This is how the Dish network And Direct TV send down some local TV station signals. They re-use the same spectrum with spot beams to different areas of the country. This is why you generally cannot pick up a local Los Angeles station if you are in say New York City...you are way outside the spot beam area and the same frequencies are in use carrying local New York stations. The satellite internet providers like Wild Blue use spot beams to target
different areas using the same frequencies, getting multiple use from their bandwidth.

If someone wanted to interfere with the downlink signal from a sat they would have to be extremely close to the
pickup dish since any signals off to the side and on the ground would be down probably at least 100db.


7 posted on 04/20/2010 10:00:33 PM PDT by Bobalu (Free men are not equal. Equal men are not free.)
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To: Bobalu
I guess I’ve been around a little too long but I remember secure earth bound comm systems that are still in existence today. The sat stuff is important but if someone needs to get a launch command they will get it no matter what.
9 posted on 04/20/2010 10:15:35 PM PDT by oldenuff2no (Proud vet)
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