state vector and Norad TLE

[dida_plt]

I have state vector (x,y,z,xdot,ydot,zdot) and i want generate norad TLE file.
please help me to find the equations.
thanks a lot

 

[Alexrey]

http://orbitsimulator.com/formulas/OrbitalElements.html

 

[dida_plt]

thank you for this link, but I want programm it (realise like this application) so I'am searching the mathematical formulas .

thanks a lot

 

[Alexrey]

I found this link: http://space.stackexchange.com/ques...rbital-elements-using-position-velocity-vecto, but if it is a little confusing then if you're able to find yourself a copy of Orbital Mechanics for Engineering Students by Howard Curtis you'll find a great step-by-step algorithm starting on page 159 and ending on page 161.

 

[dida_plt]

thanks a lot, it's very useful. :tiphat:
some element are missing to construct NORAD TLE File such us : drag term, element number, the first and second time derivatives of mean motion...

 

[StefanE]

You say you have a state vector and you want to create a TLE-File from it. You ask for terms like drag e.g.
I think there is some basic misunderstanding. If you really have only a state vector, you can derive most information for the second (!) line only of the TLE-File, but nothing for the first line. The information in the fist line can in no way be extracted from a state vector, it must come from completely different sources.

And even getting the values for the second line is no easy task. First thing is to convert your state vector into orbital elements. There are quite a few tools available in the Internet to do that, but you should also know if your state vector ist ecliptic-based or equatorial based. Once you have orbital elements you can get the values for the second line of the TLE by some calculations. If you have come that far, report back and we will help you