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Questions tagged [sgp4]

For questions regarding simplified perturbation models and their implementations, regardless of implementation language.

Simplified perturbation models are a set of five mathematical models—SGP, SGP4, SDP4, SGP8, and SDP8—used to calculate orbital state vectors of satellites and space debris in an Earth-centered coordinate frame. The set of models is often referred to collectively as SGP4 due to the prevalence of that algorithm. See the Wikipedia page for more information.

This tag is intended to be used for questions regarding these models and their implementations in any programming language.

13 questions
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Which should I use: Python-sgp4, PyEphem, python-skyfield

The landscape of Python tools that seem to accomplish the task of propagating Earth satellites/celestial bodies is confusing. Depending on what you're trying to do, PyEphem or Python-SGP4 may be more suitable. Which of these should I use if: I want…
Brian
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Efficient way to propagate satellite catalog over time

Problem statement I need to propagate the entire catalog of recent TLEs (need a free account to view) from space-track.org using skyfield or similar. There are typically 15k-16k TLEs in the list. I have it working, but it is very slow. On the order…
Engineero
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Skyfield: achieve sgp4 results with 1 second periodicity for given time interval

I've implemented sgp4 algorithm using Skyfield in python. I need the position vector for 1 day time interval with 1 second periodicity. For that, I have to calculate the sgp4 repeatedly, adding 1 second each time. Is there a way to return a vector,…
Leeloo
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How can I use skyfied to convert SGP4 TEME coordinate to ECEF?

I want to plot the satellite tracking on a map. So I use SGP4 1.4 with python .Input the TLE data, but the outdata is not what I want. So I want to convert the output data to the ECEF data and get the longitude and latitude. I know the skyfied can…
X.H Cui
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3
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Units in sgp4 orbital calculations

I'm doing a project to calculate vector positions of a satellite using the package sgp4. Given an input file, it's supposed to spit out a position vector in metres from the centre of the earth. However, in the example given, and in all outputs I…
Jon Martin
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Why am i getting a difference between matlab's "lla2eci" and "sgp4.propagate"?

I am not experienced in this area but over the past few days I've put together some code in python that tracks (hopefully) the ISS. I've done the math and have that side of things working, but only when I inject the satellite position using…
jtatro
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outputs not matching from sgp4 in C++, pyephem and Heavens Above

I am trying to predict calculate the positions and predict passes of a LEO satellite from a TLE file. For convenience I just take the international space station. What I did so far, is to download the spg4 libraries sgp4 libraries for C++ and…
Bloch
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Python SGP4 1.1 Calculating Incorrect Orbit

I am using the python SGP4 1.1 module to calculate the position and velocity of a MEO satellite. I'm noticing when compared against STK and JSatTrak that the returned values for position and velocity are incorrect. The Satellite should have a…
user2156697
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Java Code gives different results on android

I have some code, running on the PC as just java code, it gives the answer I want (the right one). On android the same code gives very different answers. The code I am using was originally from the JsatTrack project, and gives these answers jun as…
Rob
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why skyfield satellite position reading calculations are different from n2yo?

I am trying to track the satellite and getting its location in form of latitude, longitude and height from TLE data. But when I try to match it with the realtime readings on n2yo website, my latitude has difference of 5 degree and longitude…
Rahul Sharma
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No module named 'sgp4' but Requirement already satisfied: sgp4 in c:\

New to coding so appreciate this might be obvious - throwing an error at line 1: from sgp4.earth_gravity import wgs84 which returns: "No module named 'sgp4' " however when I go to install using pip I'm told: "Requirement already satisfied: sgp4 in…
N Godrich
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How to parallelize calculations of celestial bodies motion?

I have a piece of code which calculates positions of some satellites and planets using Skyfield. For clarity, I use Pandas DataFrame as a container of positions and corresponding time moments. I want to make calculation parallel, but always getting…
lazySeal
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How to install SGP4 V 1.4 package in Python 3.6

First post hear and relatively new coder. Trying to get this package: https://pypi.python.org/pypi/sgp4/ to work, only I have no idea what I'm doing. I'm not familiar with the file extension (.tar.gz) and I don't know if this is a module or what and…
Lorcank11
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