Me earlier: "Also, align your telescope's mounting so that you are mostly slewing in one dimension --makes it much easier. Think of the satellite's path across the sky as an approximation to a great circle. Point one axis of the scope's mounting towards the pole of the great circle." I think I can put this in more practical terms. Find the point of max elevation. Point one axis of the telescope to the spot in the sky that is 180 degrees away from that point in azimuth and complementary to it in altitude (90-max altitude). An example: suppose the satellite you're chasing reaches max altitude at 70 degrees in the northeast (azimuth=45). Point one axis of your mounting towards the southwest at an altitude of 20 degrees. This will generally align motion about that axis along the path of the satellite so that you only have to slew in one dimension. And don't just think in terms of the polar axis of your mount. You can pick either axis based on what's physically convenient with the mount of your scope. By the way, this trick also applies to chasing very faint satellites. If you're hunting something at, say, tenth magnitude, and the orbital elements are good, you can point the scope at exactly the right spot and wait. When you see it zip across the field of view, you'll want to chase it, but it's easy to get ahead or behind and lose such a faint object. If the scope is aligned to slew approximately along the path, you'll be able to sweep it up again in many cases. -Frank E. Reed Chicago, IL ----------------------------------------------------------------- Unsubscribe from SeeSat-L by sending a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@lists.satellite.eu.org http://www2.satellite.eu.org/seesat/seesatindex.html
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