The angle ARE is half that.

The length RE is therefore cos(360° × (3000/24902) /2 ) × 6,378km

RE = cos(21.685°) × 6,378km = 5,927 km

AE = sin(21.685°) × 6,378km = 2,357 km

So distance ED = (6,378-5,927) + 830 = 1,281 km

We now know AE and ED, so the angle from that is:

tan-¹(2,357/1,281) = 61.5°, and you need to double that to 123° --> ANSWER = 123°

There may be an easier way to get there, I just went about soloving triangles till I got there.

]]>Note: All I was given at the start of the problem was the swath coverage = 3000km (the curved area of the earth the satellite sees) and the altitude of the satellite = 830km.

http://img.photobucket.com/albums/v145/sealcock6/sat_swath_angle.jpg

if you have any questions please reply

]]>The measurements sure do sound like this planet.

]]>It is just a *little* bit hard without a diagram!

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