The ones I used for my initial calculations were dated 03346.08309035, about a day older than yours, which makes since since I downloaded them a few days ago. That you are using newer TLEs could account for the difference. The current ones are dated 03347.85162037 but I have not run them yet. I plan on one final run the night before the transit to see if the orbit has changed. I get my TLEs from the NASA/GSFC Orbital Information Group site. If you're not registered there you need to register first. Do that at: http://oig1.gsfc.nasa.gov/scripts/foxweb.exe/newappl@app01?tdac=B6XRQIDBJIBS... Patrick James Cobb wrote:
What orbital elements are others using for ISS? I downloaded
ISS (ZARYA) 1 25544U 98067A 03347.16153959 .00012592 00000-0 12817-3 0 8862 2 25544 51.6285 197.0395 0006049 240.9758 218.2116 15.65542665288988
from NORAD http://celestrak.com/NORAD/elements/stations.txt
Is there a better source of elements I should be using? Using xephem I'm not quite getting agreement on the timing of the transit with other predictions I've seen on this thread.
Alternatively, how about Delta T (i.e. TT - UT1)? Xephem uses a value of 67.45.
It would be interesting to compare the predictions of the various charting packages and the observed timing0