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DougSlug · Guest

When I display the maximum Orbit/Ground Track Length in the 3D View, the tracks for the GPS satellites appear to be a sort of hyperbolic paraboloid ("saddle") shape. Every reference to the GPS orbits that I found (including a discussion with a colleague who previously worked with satellites) indicates that the GPS orbits are circular. Am I misinterpreting something, or is there an error in the track display? I am new to satellite tracking, and I'd like to understand this one.

Thanks,
Doug

P.S. SatScape has fully impressed everyone I have shown it to, including the aforementioned "rocket scientist" colleague. The program has taught me so much in a very short time...I use it for AMSAT tracking. - D

satscape · Posted: Sun Sep 05, 2004 3:09 pm Post subject:

Yes, thats normal. Every satellite orbit is elliptical or circular, but as the 3D View works by keeping the earth fixed, some orbits can look a little strange. To make things a little clearer, try using the "time-warp mode" on the menu, and adjust it to full speed, you can see from that, that the GPS satellite is just going around in a 12000 mile circle, but as the earth is spinning, it can distort what the path looks like.

Its a similar effect to looking at the 2D view, satellites appear to fly around in a sine-wave shape, its just the effect of looking at a 3D world on a 2D display.

Scott