How to get TLE from Keplerian?

I want to convert Kepler to TLE, what to do? Please help, thank you!

Hi @hurricane313622

Let kepOrbit be your KeplerianOrbit, you can convert the orbit to a TLE using: TLE.stateToTLE(new SpacecraftState(kepOrbit), templateTLE);

The template TLE is a TLE object used to access some spacecraft information like satellite number, launch year, etc. It is not used to access the orbit since it is the job of the stateToTLE method to compute it :slight_smile:
In other words, you can set the orbital parameters to 0.0 in the templateTLE.

To initialize the templateTLE, you can use the following page : Two-line element set - Wikipedia

Best regards,

Hi Bryan,

the B* is not reused as well?


Yes, the B* from the templateTLE is also reused. There is no B* estimation in the stateToTLE method.


For TLE fitting (including B* estimation) they are interesting topics in the forum:

Okay, I’ll give it a try in your way. Thank you!

Hi, Hello. I have implemented the conversion, but how can the Revolution number in TLE be calculated?

If I understand well (@MaximeJ), the revolution number represents the number of revolution performed by the satellite at the TLE epoch. It is incremented by the stateToTLE method. For instance if your templateTLE is 24 hours before your kepOrbit and if your satellite has an orbital period of 12H, the final value in the generated TLE should be the previous one +2.

When initializing the templateTLE, if you don’t know the revolution number, just set it equal to 0.


Thanks.I’ll give it a try.