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Questions tagged [skyfield]

Skyfield high precision scientific astronomy library for Python and NumPy

The Skyfield project provides a modern alternative to the elderly PyEphem astronomy library for Python. Instead of requiring a custom C extension to be built or installed, Skyfield does all of its computation in pure Python and requires only the NumPy high performance numeric library in order to do its work — making Skyfield perfect for developers who can install NumPy directly, or who use scientific distributions that install NumPy automatically.

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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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python convert au to km

I'm trying to write a very simple programm, that prints the current distance to any planet in kilometers. I'm using Skyfield. Here's my code for Mars: from skyfield.api import earth, mars, now ra, dec, distance =…
Monotom
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skyfield star location numbers

I've downloaded Pandas and I'm fine with Skyfield planets. I want to find the hipparcos location numbers of stars. Rhodes Mill tutorial only has one example listing the Barnard Star. How does python/ skyfield access these star locations? e.g How do…
sybe
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Calculating satellite apogee and perigee from TLEs using skyfield

I'm trying to calculate the perigee and apogee of a given satellite based on its TLE from skyfield.api import Topos, EarthSatellite ts = load.timescale() # latest TLE as of this morning, epoch is epoch=2020-08-24T12:30:01Z line=['0 ISS (ZARYA)', …
rtphokie
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Is it legit to generate a TLE (Two-Line-Element) file from instantaneous Kepler elements?

Since TLE Elements are in essence mean elements, is it possible to generate a TLE from instantaneous Kepler elements?
fl0ta''
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How do I compute correct planet oppositions?

I'm having a hard time to find a way to compute the exact moment when a planet comes in opposition. By definition, planet is said to be in opposition when, from the point of view of Earth , it is at the opposite of the Sun , so my assumption was…
Deuchnord
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Calculate the tilt of the moon crescent

Is it possible to calculate the tilt of the moon crescent with Skyfield? Or directly? I know the crescent rocks back and forth and I would like to display it correctly. https://www.calsky.com/cs.cgi/Moon/15?obs=4311082095747103&c= #…
SirDagen
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Is there a way to know date and time given the coordinates of a planet (sun,moon etc.)

Skyfield has the functionality to compute the phases of the moon. but What if I wanted to know when would the moon be 20 degrees from the sun or 25 degrees from the sun. How can I get the exact date and time when the sun and moon would be at a…
AviD1511
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How to find satellite relative velocity in skyfield?

I need to find how fast a satellite is moving relative to me. I was thinking about using the Python package 'skyfield' but I don't see how I can calculate this: from skyfield.api import EarthSatellite, Topos import skyfield.api sat =…
jeremy
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Skyfield year is out of range

I'm trying to use Skyfield to plot an orbit, but it doesn't work. Here's the code: import numpy as np import matplotlib.pyplot as plt from skyfield.api import Loader, Topos, EarthSatellite text = """ GOCE 1 34602U 09013A 13314.96046236 …
Gordon13
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Find (ra,dec) from an (azimuth,elevation) in skyfield

I have a directionnal antenna on Earth and I would like to know where it points to in ra,dec coordinates. I'd like to use the new skyfield library for that, as pyephem is not developped anymore. It is easy to compute my topos position on…
nixx
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finding twilight times with skyfield

I have a function that returns the sunrise, sunset, solar-noon and twilight times for a given location. This function uses pyephem and since it's deprecated, I'd figure I'd re-write the function to use skyfield. However, skyfield doesn't have the…
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Skyfield and apparent diameter

Can Skyfield calculate the apparent diameter of a planet, the Sun or Moon? Something along the lines of: place.at(utc).observe(moon).apparent().angular_diameter
rtphokie
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How can I get Skyfield to agree with the Nautical Almanac for the Sun's Declination?

Here's a sample script that calculates the sun's declination on 2016/7/23 at 00:00:00 GMT using both PyEphem and Skyfield: import ephem sun1 = ephem.Sun('2016/7/23 00:00:00') dec1 = sun1.dec print 'PyEphem Declination:',…
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