Hi, I recently started imaging geosats using a popular web-based observatory. So I decided to make a spreadsheet to aid in satellite location. I'm sure you all must have similiar (and probably better) tools for this purpose but I offer it here, FWIW. The spreadsheet will calculate the subpoint longitude corresponding to a geosatellite's observed azimuth. It will also generate a table of Clarke Belt "look angles" with user-specified minimum elevation limit and longitude step. (Or alternatively, just enter a list of satellite longitudes by hand.) Additionally, it provides RA/Dec coordinates corresponding to geosat look angles for user selected date & time. It has a convenient macro "hotkey" for generating the data table without need of manual cut&paste of cell formulas, etc. I have found this spreadsheet to be useful in generating Clarke Belt 'horizon' data for my HNSKY planetarium program for my home site and remote imaging site. And, mainly, it provides accurate RA/Dec targeting info for scheduled short duration point & shoot missions on the web-based scope. It is sufficiently accurate to routinely target seven Astra satellites in 25 arcmin fov. (If anyone needs the format for the HNSKY horizon file, I will be happy to provide that as well: displays the Clarke Belt as an arc with alternating red & white segments with subpoint longitude labels at 1 degree intervals. You would need the spreadsheet to generate your own local position data, of course.) The xls spreadsheet is 158k, zipped. I could upload it to a files section if available (please advise), else mail to anyone who wants it. -- Drew ------------------------------------------------------------------------- Subscribe/Unsubscribe info, Frequently Asked Questions, SeeSat-L archive: http://www.satobs.org/seesat/seesatindex.html
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