Linked Questions

21 votes
3 answers
25k views

How can I plot a satellite's orbit in 3D from a TLE using Python and Skyfield?

I have obtained a Two Line Element (TLE) of a satellite in Earth orbit from Celestrak at https://celestrak.org/NORAD/elements/ and I would like to use it to calculate an orbit. How can I calculate the ...
uhoh's user avatar
  • 149k
10 votes
3 answers
2k views

Will the new "TLE format" be orbitally-mechanically better than traditional TLEs?

Celetrak's A New Way to Obtain GP Data (aka TLEs) by Dr. T.S. Kelso 2020 May 27 explains the arrival a new infoblob format that in several ways is "better" than the ancient TLE, and contains ...
uhoh's user avatar
  • 149k
9 votes
4 answers
805 views

How do cubesat owners first find out their cubesat's initial trajectory? How do they point antennas at it before official TLEs start to appear?

When cubesats are first deployed it can sometimes take several days before they start appearing in official TLE distributions, and even then if many were deployed it may take a lot more work to decide ...
uhoh's user avatar
  • 149k
12 votes
3 answers
1k views

Why are Tiangong-1's Apogee and Perigee Graphs Wobbly?

The apogee and perigee graph of the Tiangong-1 space station, about to re-enter and break up Real Soon Now, is depicted in this graph (source: Wikipedia): Why are the graphs wobbly? Is it because the ...
Jens's user avatar
  • 1,696
3 votes
3 answers
3k views

what does Check sum TLE mean?

I am doing a report on TLE's and I was looking up what the numbers mean. I found a very helpful site. See here: http://spaceflight.nasa.gov/realdata/sightings/SSapplications/Post/JavaSSOP/SSOP_Help/...
Qorzyking's user avatar
5 votes
2 answers
1k views

Sun-synchronous satellite orbit propagation

I'm trying to propagate the orbit of a sun-synchronous satellite. The initial data is defined by the TLE. The orbit of the satellite is controlled by the operator ...
Tarlan Mammadzada's user avatar
5 votes
1 answer
4k views

TLE SGP4 Coordinate Transformations

I am working on developing a user friendly SGP4 orbit propagator in C on a PIC24. I have extensively read Revisiting Spacetrack Report #3 and celestrak - there are a few outstanding questions I have. ...
Ashton Meginnis's user avatar
4 votes
2 answers
939 views

What is/was legacy TLE ephemeris type 2? (TLE, line 1, column 63)

Wikipedia's Two-Line Element Set entry for line 1, column 63 (1.12) says: Ephemeris type (internal use only - always zero in distributed TLE data)13 13Celestrak Frequently Asked Questions: Two-Line ...
uhoh's user avatar
  • 149k
3 votes
2 answers
929 views

How to correctly make a fake, counter-propagating TLE?

In this answer I have said: Do not make FAKE TLEs! I would now like to make a fake TLE. Specifically I'd like to generate a counter-propagating "twin" of an orbit by flipping inclination by 180° ...
uhoh's user avatar
  • 149k
4 votes
1 answer
616 views

Computing a new TLE following a delta-v impulse?

Is there some code or a library out there that can take orbital elements, add a known delta-v component and then compute a new TLE? I found this one https://apps.dtic.mil/dtic/tr/fulltext/u2/a289281....
dreed75's user avatar
  • 41
5 votes
1 answer
2k views

Calculating J2 perturbations in cartesian coordinates?

I am an engineering student and we have taken upon a project that involves modelling the motion of earth satellites. So far we have a model that uses numerical symplectic integration to solve the ...
Arian's user avatar
  • 51
4 votes
1 answer
2k views

Python orbit simulation using TLE-tools and poliastro

I have a source of satellite TLE data - similar to space-track.org. For testing purposes I would like to create a simulation that doesnt rely on the real source of data. I was able to download a json ...
wolf72's user avatar
  • 141
2 votes
1 answer
1k views

SGP4: propagation initialization by state vector

I'm using the SGP4 model to propagate the orbit, initialized by TLE from celestrak.com ...
Tarlan Mammadzada's user avatar
3 votes
2 answers
231 views

PseudoTLE creation

I am developing a script in python to obtain pseudo TLEs of a satellite, starting from its state vector. I have always used TLEs to propagate the satellite and predict its next pass over a ground ...
Luca Pizzuto's user avatar
2 votes
1 answer
327 views

In MATLAB, Computing a new TLE/orbit following a delta-v impulse?

I have already worked on this project for a week, and I still can not solve this problem by myself. How can I update data for the SGP4 OrbitPropagator in Matlab's ...
Achilles chan's user avatar

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