Linked Questions
24 questions linked to/from How do SDP4's "Deep space" corrections to SGP4 account for the Sun's and Moon's gravity?
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Confused about SGP4 implementation published by celestrack
I was trying to understand how SGP4 computes the propagated position I had a look on the original publication paper but i have not found a satisfactory answer.
So I had a look to the Matlab ...
CommunityBot
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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.
...
CommunityBot
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SGP4 on Systems Tool Kit (STK); how to check if SDP4 deep space correction is implemented?
I am doing orbit propagation for a geostationary satellite which requires the deep space corrections of SDP4. See my previous question SGP 4 for Geostationary Satellite.
I am using SGP4 on STK, but, ...
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Differences between SGP8 and the standard SGP4? Is it ever used in practice?
The Wikipedia article Two Line Element Set says:
The SGP4 model was later extended with corrections for deep space objects, creating SDP4, which used the same TLE input data. Over the years a number ...
CommunityBot
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In a 3D space defined by semimajor axis, eccentricity and inclination, what would be the shape of the space where SDP4 works better than SGP4?
@BillGray's answer to Why can't custom-made TLEs for the DSCOVR launch booster in orbit around Earth work with SDP4? is quite interesting and informative; I fail to do it justice by summarizing it as ...
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For any state vector of a satellite at an arbitrary time T1, is there another state vector at a given time T2 that will result in the same orbit?
I recently found the question In a 3D space defined by semimajor axis, eccentricity and inclination, what would be the shape of the space where SDP4 works better than SGP4? and have become interested ...
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Is the amount of accurate information in a TLE equal to that of a single state vector?
My question is basically regarding whether there is orbital information "lost" when converting from a Two Line Element set (TLE) to a state vector.
Given that the following are true:
I have a TLE, ...
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Is SGP4 propagation necessarily more accurate near the epoch chosen for TLE generation?
This interesting answer includes a quote from Space-Track:
From Space-Track.Org FAQ
TLEs can contain future epochs.
About 20 satellites are categorized as "multi-day objects" because ...
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Textbook or scholarly discussion of equations used by the SDP4 part of SGP4 TLE propagators beyond Space Track Report #1?
(the famous) Space Tract Report #3 discussed at length in Dr. T.S. Kelso's Revisiting Spacetrack Report #3, AIAA 2006-6753 Describes the "deep space" corrections to the original SGP4 known ...
CommunityBot
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Why can't custom-made TLEs for the DSCOVR launch booster in orbit around Earth work with SDP4?
This fascinating answer to Why has no TLE been published for the DSCOVR satellite and the Falcon 9 R/B? presents links to custom-made TLEs for the Falcon 9 rocket body that put DSCOVR into orbit, and ...
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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 ...
CommunityBot
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How to calculate the very special orbit of 2020 SO
From a NASA JPL page:
Earth May Have Captured a 1960s-Era Rocket Booster
Source
(Sorry, I got an error when I tried to include an animated gif.)
2020 SO was captured by Earth's gravity on Nov. 8, ...
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Cis-L2 Libration Point Halo Orbit
Queqiao became the first satellite to orbit the Cis-L2 libration point (far side of the moon). Link: https://en.wikipedia.org/wiki/Chang%27e_4
Does anyone have any insight on how to model this orbit ...
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Get dates when a satellite has performed maneuver from historical TLE data (python)?
I have been recently acquainted with orbital mechanics and am trying to do some analysis on the subject. Since I don't have subject matter expertise, I am at a crossroads with trying to decide that ...
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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 ...
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