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.

24 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
6 votes
0 answers
103 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 ...
Mark's user avatar
  • 525
4 votes
0 answers
895 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 ...
Cristiano's user avatar
  • 1,760
4 votes
0 answers
118 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 ...
Niladri Das's user avatar
3 votes
0 answers
218 views

How to generate TLEs based on a set of observation points (location, azimuth, elevation... no range)

I'm interested in generating a "corrected TLE1" based on observation data. I would have observed azimuth and elevation, site location, and time. All of those data fields are observed with ...
Judd's user avatar
  • 91
3 votes
0 answers
45 views

Where can i find ELSETS with Co-Variances?

For Special Permutations (I'm a novice), an ELSET with covariance is more accurate than without covariance. A TLE doesn't have room for any covariance. However, I can't seem to find a catalog that ...
Barry vT's user avatar
  • 321
3 votes
0 answers
90 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 ...
Craeft's user avatar
  • 473
3 votes
0 answers
64 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 ...
uhoh's user avatar
  • 149k
3 votes
0 answers
84 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.
MScott99's user avatar
3 votes
0 answers
117 views

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 ...
Daniel's user avatar
  • 31
2 votes
0 answers
122 views

How do I know the exact TLE of my satellite after its deployment?

The satellites are launched in a cluster. How can I validate the TLE of my satellite in the early days following deployment, because there are more than two satellites that are close to each other and ...
Auberron's user avatar
  • 1,485
2 votes
0 answers
272 views

Calculating Which Satellite Passes are Visible - Need help

I am a beginner Python programmer. I am trying to get the code in the article "Calculating which satellites are visible" to function without success. My plan is to identify satellites that ...
Jeff's user avatar
  • 21
2 votes
0 answers
127 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 ...
user6916458's user avatar
2 votes
0 answers
67 views

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 ...
uhoh's user avatar
  • 149k
2 votes
0 answers
80 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: ...
Cristiano's user avatar
  • 1,760
2 votes
0 answers
301 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 ...
Andreas Ioannou's user avatar
1 vote
0 answers
301 views

Is there a python library to determine the position of a satellite at a given time from TLE data excluding the Satellite catalog number?

Or perhaps some simple code or formula that achieves this. I've used pyephem but it requires a Satellite catalog number.
Imp's user avatar
  • 61
1 vote
0 answers
105 views

Issue with propagating TLE sets using SGP4

I am trying to make some analysis on conjunction events using the TLEs available from Celestrak's SOCRATES page. Take for example the following predicted event: Here's my issue: when I try to ...
gio_ros's user avatar
  • 21
1 vote
0 answers
592 views

calculating satellite position and velocity from TLE

I'm trying to calculate satellite orbit from the TLE set at first, I used several libraries including SGP4, Skyfiled to get the initial position and velocity of the satellite at the epoch time I know ...
abdalla's user avatar
  • 63
1 vote
0 answers
53 views

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 ...
Acabit 93's user avatar
1 vote
0 answers
34 views

Did Tianzhou-2 have a TLE before docking with Tianhe 8 hours after launch? Which is the 2nd stage rocket body and roughly how soon will it reenter?

Clicking on https://celestrak.org/NORAD/elements/stations.txt I get ...
uhoh's user avatar
  • 149k
1 vote
0 answers
620 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 ...
Artur's user avatar
  • 11
1 vote
0 answers
767 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 ...
mikesneider's user avatar
0 votes
0 answers
113 views

Use ECI cordinates to plot orbit in three.js

I am using satellite.js to get ECI coordinates from TLE data. Now my first question is can ECI coordinates be used to plot satellite orbit as shown here. If yes then how can i do that in three.js? ...
Sourav Anand's user avatar
0 votes
0 answers
92 views

Is Vallado's Revisiting Spacetrack Report #3 still relevant today?

The title pretty much sums it up. I am reading David A. Vallado's Revisiting Spacetrack Report #3, which was published in 2006 and includes source code for the SGP model series. I was wondering, is ...
lawndownunder's user avatar