Set of values carefully prepared to be used together with a simplified perturbations model (most often SGP4) to predict satellite positions with a moderate level of accuracy for times near the epoch contained within the TLE.
Questions tagged [two-line-elements]
111 questions
12
votes
2 answers
Obtain archived TLE data
Now I'm achieving the up-to-date TLE from the celestrak.com and tle.info
However, for some analysis in the past, I need old TLE files, to make my calculations more accurate.
Is there a way to obtain the archived TLE data? Is there a way to do it via…
Leeloo
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7
votes
2 answers
How to Update the Epoch in a Fake TLE While Maintaining Relative Position?
I've been trying to compare before & after results for some updated algorithms in an application. Basically, I want to be able to start and run the test at any arbitrary Epoch with the satellite starting in the same position relative to a fixed…
The Dan Hammer
- 123
- 5
5
votes
1 answer
Recreating the eccentricity value of TLE
I cannot confirm the eccentricity value of a TLE using corresponding position and velocity vectors.
Let me go through an example, ISS, to explain the situation.
Using this TLE for ISS,
1 25544U 98067A 17198.89938657 .00000988 00000-0 22167-4 0…
VolkanOzcan
- 658
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3
votes
1 answer
What is the "+" symbol for the drag term encoded in a TLE?
I have two TLE, the drag term for the first TLE is -26868-1, which I suppose equals to -0.026868. But on the second TLE, we have 00000+0. What does the "+" symbol represents here?
COSMOS 2549
1 47546U 21008A 21040.52165678 -.00037182 …
lawndownunder
- 537
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2
votes
1 answer
How to make my generated two line elements more accurate?
I am using Orekit to generate TLEs. I am then propagating those elements out and comparing it to the ephemeris used to generate them. This results in a residual error in excess of 20 km. I am not exactly sure why my answers are so off. Is there any…
tarcin
- 121
- 1
2
votes
0 answers
CSpOC’s identical TLEs
Identical TLEs are often published by CSpOC at https://www.space-track.org/.
For example, here’s the first line of the three newest TLEs for IRNSS-1H:
1 42928U 17051A 19061.11119682 .11183803 -20635-4 33328-3 0 9993
1 42928U 17051A …
Cristiano
- 1,760
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1
vote
1 answer
change epoch to ( epoch year and Juilan day fraction )
the question asks you to make two line element it give you the given information and also everything is answered but the one thing i don't understand in here is how do the change the Epoch 29 sep 2010 18:00:00:00.000 to 10272.41666666. i need…
user54651
- 21
1
vote
0 answers
Given the measured positions of an object, how to retrieve its latest TLE?
I'm working on a simulation space project, in which I simulate the positions of all the Low Earth Orbit objects at any time.
For the moment I have a 3LE database of LEO objects, and each time a ground based telescope detects an object, I can compute…
Acabit 93
- 11
- 3
1
vote
1 answer
Distance between GRACE-FO 1 and 2
I calculated the distance between the two satellites by propagating some TLEs with the SGP4. Here’s the result:
the solid lines are for TLEs 19197.90524586 (GRACE-FO 1) / 19197.90551489 (GRACE-FO 2) and the dashed lines are for TLEs 19195.14720185…
Cristiano
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