Questions tagged [two-line-elements]

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.

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How can I plot satellite's trajectory from three different TLEs to detect any deviation on path with time?

I have obtained TLE information of a satellite from space-track.org for three different times. I am trying to study any deviation of the satellite trajectory from its usual path. Here I am comparing ...
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96 views

What happens when the 3-letter suffix space of a SATCAT ID gets exhausted?

The ISS' SATCAT ID is 1998-067A. The CubeSats and other objects released from the space station are considered its sub-units, thus using different suffixes: 1998-067C, etc. The same principle applies ...
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110 views

Equinoctial Elements and Perturbative Effects

I have an Orbital model in Equinoctial Elements (paper). There is a perturbative acceleration term in the model. Can someone point me to some relevant papers showing how to include different ...
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40 views

Second derivative of mean motion as indicator of deorbit

I noticed that the second derivative of mean motion (SDMM) is non-zero for only a small percentage of the NORAD catalog. All those objects I checked have reentered since the TLEs I was using were ...
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58 views

Pre-launch TLEs for NASA launches

I was curious if the United States is on the verge of launching maned flights to the ISS, will anyone release Pre-Launch TLE data like was done back when the shuttle was flying.
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Regarding the vernal equinox and calculate a TLE code

I am utterly confused as to how the ecliptic co ordinate system works. My understanding is that the vernal equinox is comparable to greenwich for longitude here on earth. But how do we know where the ...
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81 views

Where can I find a satellite/space debris database with object masses

The title pretty much says it all. As far as I can tell the default method by which space debris objects are tracked/stored in a database is using two line element sets. However these have no way to ...
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31 views

Where is this LightSail-2 trajectory data coming from? Is there more than TLEs available to the public?

This tweet shows high granularity data for LightSail-2's perigee and apogee, showing that while the apogee-raising strategy is working nicely, currently atmospheric drag is taking its toll and the ...
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How can I “debounce” these TDRS satellite inclinations? (reconstruct the zero-crossings)

The plot below is from the question Why do the geosynchronous TDRS satellites have this distribution of inclinations?, and the explanation says Inclination and mean motion (rev/day) for TDRS ...
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68 views

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: ...
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530 views

TLE/SGP4 state vector accuracy assessment

I’m using the Planet Labs state vectors downloadable from http://ephemerides.planet-labs.com/planet.states or http://ephemerides.planet-labs.com/planet_YYYYMMDD.states to assess the TLEs/SGP4 accuracy ...
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163 views

How can I plot a precessing orbital plane of an artificial satellite on a polar plot from a TLE in Python?

How can I plot the orbital plane of an artificial satellite on a polar plot from a TLE in Python? Very new to all of this. As I understand it I need to extract TLE's from Space-track.org. Then use ...
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220 views

How can I plot a satellite TLE from its orbital parameters using python and skyfield?

I have a function that uses TLEs (Two-line elements) from Celestrak to plot the visibility of a satellite in Python. Is there a method with skyfield or poliastro to plot a TLE from given orbital ...
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356 views

Calculate ground track from CCSDS OEM

Are there open source solutions (preferable Python) to calculate the ground track of a spacecraft (i.e. in latitute/longitude) from CCSDS OEM (orbit ephemeris message) format (which is a dataset of ...
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554 views

Elevation and Azimuth of satellite in different location

I know the Elevation and Azimuth of the a specific GPS satellite (I have the RINEX files of the station in a specific Location 4.4801,-73.3433; in order to calculate this), but I want to know the ...
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488 views

PRN number in TLE files are the same in RINEX files? (in GPS constellation)

I want to compare the position calculated with Pyephem and TLE files, with RINEX files and GPSTK library in a specific date and time, but I have not the certainly if the name of the satellite "PRN ##" ...
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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 ...