Overview of tools for asteroid observers on this site
Use the form below to get ephemerides for artificial satellites. You can enter an artsat designation, and/or click on the check-boxes for various artsats listed below. The artsats with check-boxes are some high-altitude objects that occasionally get mistaken for asteroids. You can generate ephems for any catalogued artsat, including those in low-earth orbit, but much of this service is oriented toward the asteroid hunting community. We're usually tracking the high-altitude stuff.
You can, of course, select multiple objects and get ephemerides for each of them.
Please note that this is a work in progress. At some point, there should be an option to suppress daytime and below-the-horizons ephems. Ephemerides in JSON output would be an aid to automation.
Ephemerides are generated using the same TLEs (Two-Line Elements) as are used for the artsat identification tool, and have roughly the same limitations. Like that tool (and basically all tools on this site), source code is freely available, and you can build the code to run on your own machine instead of/as well as an on-line service.
Ephemeris starting date : This 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.
Step size: This defaults to being in days, but input such as '2h' will lead to a two-hour ephemeris step size, or '10m' for a ten-minute step size. One can use '.1' to get a step size of a tenth of a day, and so forth. Negative step sizes will result in a backwards-running ephemeris.
MPC code: This defaults to 500, for a geocentric ephemeris. But it can be any of nearly 2000 three-character observatory codes assigned by the MPC. Or, as shown, you can specify a lat/lon and, optionally, an altitude.
I can be reached at pôç.ötulpťcéjôřp@otúlm. If you're a human instead of a spambot, you can probably figure out how to remove the diacritical marks...