Download latest orbital elements

To receive APT accurately you will need to update the orbital elemets continuously and have your computer clock in synchron with a time server. For our purposes we recommend you to update every week.

To update the orbital elements click on menu Satellite -> Keplerian elements... Enter the URL (full path to the TLE), Group name, and set Download to Yes and finally click the Download button. If you want to refresh and download again, highlite the URL and click on Remove timestamp and again click the Download button.

The orbital elements are saved to folder aptdecoder\kepler

Once you have downloaded the file(s) click on tab Downloaded Satellites and tick the satellites you are interested in. Finally to apply updates click the Ok button.

The URL's we are interested in are http://celestrak.com/NORAD/elements/noaa.txt, http://celestrak.com/NORAD/elements/weather.txt and http://celestrak.com/NORAD/elements/tle-new.txt when there is a new satellite launch.

You can also update from a local file by clicking on the Load from file... button. The first line in the file must be the satellite name. The next two lines are the orbit parameters.

NOAA-19
1 NNNNNC NNNNNAAA NNNNN.NNNNNNNN +.NNNNNNNN +NNNNN-N +NNNNN-N N NNNNN
2 NNNNN NNN.NNNN NNN.NNNN NNNNNNN NNN.NNNN NNN.NNNN NN.NNNNNNNNNNNNNN

After you have loaded the file succesfully the procedure is same as described above.

Read how to activate an APT satellite
Read how to synchronize time

Stay up-to-date

To automatically tell aptdecoder to update orbital elements you selected above open the General settings dialog (from menu Settings) and click on tab Custom -> System.

To enable this feature tick Update Keplerian elements... and set how frequently it should check for updates. An internet connection is requred.