EarthOrientation.jl
Calculate Earth orientation parameters from IERS tables in Julia.
Installation
The package can be installed through Julia's package manager:
Pkg.add("EarthOrientation")Quickstart
Fetch the latest [IERS][iers-link] tables:
using EarthOrientation
EarthOrientation.update()Get the current Earth orientation parameters, e.g. for polar motion:
xp, yp = polarmotion(now()) # arcsecondsOr the current difference between UT1 and UTC and the associated prediction error:
ΔUT1 = getΔUT1(now()) # seconds
ΔUT1_err = getΔUT1_err(now()) # secondsAvailable data
- Polar motion:
- x-coordinate of Earth's north pole:
getxp - y-coordinate of Earth's north pole:
getyp - both:
polarmotion
- x-coordinate of Earth's north pole:
- Earth rotation
- Difference between UT1 and UTC:
getΔUT1 - Difference between UT1 and TAI:
getΔUT1_TAI - Excess length of day:
getlod
- Difference between UT1 and UTC:
- Precession and nutation based on the 1980 IAU conventions
- Correction to the nutation of the ecliptic:
getdψ - Correction to the obliquity of the ecliptic:
getdϵ - both:
precession_nutation80
- Correction to the nutation of the ecliptic:
- Precession and nutation based on the 2000 IAU conventions
- Correction to the celestial pole's x-coordinate:
getdx - Correction to the celestial pole's y-coordinate:
getdy - both:
precession_nutation00
- Correction to the celestial pole's x-coordinate:
There is an associated function that returns the prediction error for each data type, e.g. getxp_err.
Manual Data Management
By default the files downloaded by EarthOrientation.update() will be used. It is also possible to pass different finals.all and finals2000A.all files in CSV format.
using EarthOrientation
push!(EOP_DATA, "finals.csv", "finals2000A.csv")