Question about creating TLE

[foxittt]

Is it possible to obtain new TLE from propageted vector state with the help of Skyfield?

[foxittt]

Thanks. I will try.

[scottshambaugh]

Hi @foxittt, I deleted my comment since the code didn't work for propagated epochs. I don't know of a way to do what you're asking.

[brandon-rhodes]

I suspect that generating elements to match a state vector would involve: making sure the state vector is in the TEME frame of reference (which might require a transform); then generating osculating elements from that position vector and velocity vector; then passing those to a NumPy optimizer asking, "how does these have to be adjusted so that, when passed to SGP4 as SGP4 elements, they produce exactly that position and velocity vector?"

And NumPy would hopefully iterate until it had SGP4 producing exactly that position and velocity.

My guess is it would just require a few days of experiment and tweaking to get right.

[brandon-rhodes]

(Oh, and: the official SGP4 implementation even has an osculating-elements routine of its own to get folks started, named rv2coe_SGP4(). Take a look at it if you're interested!)