It looks like CalSky may give you current positions for geosats, but it may not be quite that simple. I noticed that in the list that I got, it included an AKM, and IUS, and an SL-nn R/B(2). All of those are of course upper stages, not payloads. Plus, I don't know if it will indicate which ones are operational as opposed to those which aren't. (BTW, I noticed that CalSky seems to have Molniyas listed -- a very different type of high orbit.) So CalSky may work for what you want, but I'll say that I've been using Mike McCants' Highfly for years, and it gives all of the predictions I want. It gives altitude/elevation and azimuth, RA and Dec (1950 or 2000), height (the orbital height, from the satellite to the subsatellite point) and range (distance from observer to the satellite, with both height and range in either miles or kilometers). You can set a step size. I usually use one hour intervals, but you can use one minute if you like. (For eccentric orbits, it adjusts the step size for perigee passes -- or something like that.) You can set a magnitude limit, etc. And this is freeware! Yes it's DOS, but that's really not so bad. It's a quick download, a small and fast and flexible program. It's available on Mike's website, on this page: http://users2.ev1.net/~mmccants/programs/index.html Highfly will generate predictions for objects with mean motion less than 9 revolutions per day; Quicksat gives predictions for objects with MM greater than 4 revs. So there are a fair number of objects for which both programs will give you predictions. In that case you can choose which format you prefer to use on a given night. So, the main things with Highfly are getting it set up and then getting orbital elements and maintaining your intrinsic magnitudes file. Once you've used it just a few times, it's very straightforward and useful. If you want graphical predictions, Rob Matson's SkyMap will give you those. Oh, I just remembered an important footnote about flashing geosynchs. They're really "near geosynchs"; almost all of them are drifting, and at various different rates. Also, almost all of them have non-zero inclinations, so they move north and south through the night. So they're not nearly as simple as operational geosats, almost all of which are right on the equator and maintain their longitude. With the operational ones with zero inclination, all you need to know is altitude and azimuth, or very straightforward RA positions, all on the same declination through the entire night. The thing is that the tumbling flashing ones can flash very brightly, and, when flashing, the maxima are many magnitudes brighter than the normal very faint magnitudes of operational ones. Ed Cannon - Austin, Texas, USA __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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