[amsat-bb] Re: satellite average elevation
bruninga at usna.edu
Tue Apr 12 05:21:52 PDT 2011
> I saw on this bb a site or note that shows the overall
> average elevatation. As I remember it elevation is
> surprisingly low for most passes. Where can I find it?
I have a sketch on my web page: http://aprs.org/rotator1.html
It shows that 70% of the time LEO satellites are below 12 degrees. The good news is that for the 30% of the time they are above say 12 degrees, they are 6 dB stronger.
You can visualize this anytime by recognizing that the radius of the earth is about 4000 miles. And the radius of a LEO satellite is about 4400 miles. So swing an arc on a sheet of paper (the earths surface), and then swing another one only 10% above it (the LEO satellite) and then draw the tangent through your station. It is amazing to see how far away the horizon is and how much time a satellite is way out there...
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