BillI see the followingThe "Auto-Solve" feature of FIND_ORBThis almost always works for "normal" objects. Near-Earth objects sometimes give it trouble, especially if it turns out that the object is headed almost straight toward or straight away from us. Satellites, both natural and artificial, usually don't work. (I'm working on both limitations.) It's always worth giving this function a try, though; it has sometimes surprised me, finding orbits with initial guesses so stupid that I never expected them to lead to solutionsI hope you can get the auto-solve to work with artifical satellites in earth orbit. While there is lots of satellites with orbits, the usa military sats are a different story, some of the orbits for them have to be made by amateur satellite observers, since the orbits for some are classified.It would be great to observe them and use your program to generate the orbital elements for them. There is programs that let you do that, but manually, which means it is more difficult to get the correct orbit, at least to me. So I look forward to the auto solve solution.AlsoAccuracy of artificial satellitesFor artificial satellites, Guide uses the SGP4 (Simplified General Perturbations) theory. It does not (yet) use the SDP4 method, which really ought to be used for objects with an orbital period greater than 225 minutes.Do you have an idea when guide will use the SGP4/SDP4 theory.Just waiting for guide 8 to come out, so I can purchase it. I thought about buying guide 7, but guide 8 should be out soon?Kevin

---

Do You Yahoo!?
Yahoo! Auctions - buy the things you want at great prices