Two Line Element

A data format used to encode the orbital elements of satellites. https://en.wikipedia.org/wiki/Two-line_element_set

Conversion To Kepler

TLE is designed for SGP4 orbital propagation, so you shouldn't really do this. Here's how to do it:

• https://blog.hardinglabs.com/tle-to-kep.html
• https://space.stackexchange.com/questions/35166/how-to-find-t%E2%82%80-and-other-parameters-from-a-tle-to-calculate-an-approximate-mean
• https://forum.orekit.org/t/tle-propagator-a-computation/681
• https://forum.orekit.org/t/conversion-of-tle/375