High-flying TLEs for a specified date

I maintain TLEs for several objects in multi-day orbits (the highest is in an 80-day orbit). You can click here for the complete set of TLEs. As you'll see, they are sorted by object, with TLEs for each day within a given time span.

This form provides access to all the TLEs for a particular day/time. Enter a date/time below and click "Get TLEs", and the TLEs that are valid for that date/time will be returned to you.

If you've questions or see problems, please contact me at p‮ôç.ötulpťcéjôřp@otúl‬m (modified to baffle spammers).

Find TLEs for:

The date/time entry is quite flexible. 'now' is the default, but one can provide dates such as '2014 dec 25', 'Feb-13 3:00', '2015/2/13 03:14:15.9', and it will be interpreted properly. (Note that one shouldn't get too sloppy; '2015-5-6' could be either May 6 or June 5, and '05-06-07' could be interpreted as a (two-digit) year, month, and day in any of six orders, probably but not definitely in the 21st century. Caveat user. I usually go with a four-digit year and three-character month; "2015 Feb 18" is unambiguous, no matter how you scramble the pieces. But essentially, if a human can figure it out, this program should be able to.)

Input such as 'MJD 12345.6', 'jd 2451545', 'now+3h', and 'Wed 3:14:16 PM' will also work; click here for the full list of time input options.

The 'Worst residual' comes from the way in which these TLEs were computed. I receive observations of these satellites, both from observers directly and via the Minor Planet Center. From these, I compute orbital elements and ephemerides. I then fit TLEs to these ephemerides. The TLE model wasn't really meant for objects with orbital periods of several days; the fit of the model to the actual motion of the satellite tends to be poor, unless you limit the time span to a day or so. The "worst residual" tells you the maximum difference between the numerically integrated motion and the motion as described by the TLE.

Accuracy will correspond approximately to the "worst residual", except in cases where the object maneuvered (some of the TLEs are for active satellites) or in cases where the observations don't cover the time you want. In some cases, the object was observed for a few days, or even hours, and has gradually gone off track since then.

Source code for this can be found on GitHub. Specifically, tle_date.c contains the extracting code.