At 15:42 17/05/00 , tlj18@juno.com wrote: > >Hello, > >Are such formulas like the above on the web somewhere? The drag equation is simple fluid dynamics Jonathon, but you will find it and other material in BOOKS on Astrodynamics. The cheapest book i know on the matter is Fundamentals of Astrodynamics by Bate,Mueller and White. The nicest is P.R. Escobal's Methods of Astrodynamics. >Also, can anyone refer me to some reference where I can make satellite >predictions with nothing more than paper, a pencil, and a TLE data set >(no computer being used)? This is possible but extremely tedious, as it amounts to turning yourself into a computer. With a scientific calculator (for the Trig functions) you could probably do 1 or 2 predictions per hour less if you used a book of mathematical tables. The early chapters of any book on celestial mechanics or astrodynamics will show you what steps are required to go from orbital elements to satellite position. Escobal even discusses an algorithm to decide satellite rise & Set. You might find the discussion given by TS Kelso, on his website archive (www.celstrak.com) of articles he has written for magazines about using TLEs. The graphical methods of predicting satellites, illustrated in King-hele's book on observing Earth satellites, and used in the late 50s and early 60s by those of use observing then, assumes that lists of equatorial crossing times or orbit apex times were available. These had to be calculated with a computer at a central location. The original TLEs were a minor part of NORAD output, the rest of the information being lists of equatorial crossing times and longitudes, and a table giving offsets in time and longitude for other latitudes. In my own case, I looked for suitable positions by eye, calculated longitude, latitude by hand, solved the spherical triangle by hand using mathematical tables to give distance and azimuth, and used a graphical device to convert great circle distance & height to elevation angle. This process took me 20 minutes pre prediction. A computer is so much quicker Tony Beresford ----------------------------------------------------------------- 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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