DelaunayArgs

Container holding the Delaunay arguments of the Nutation Theory.

Fields

• M – Mean anomaly of the Moon, in radians.
• S – Mean anomaly of the Sun, in radians.
• F – Mean longitude of the Moon minus mean longitude of the ascending node, in radians.
• D – Mean elongation of the Moon from the Sun, in radians.
• Ω – Mean longitude of the Moon's ascending node, in radians.

delaunay_anomaly_moon(m::IERSModel, tdb_c::Number)

Compute the mean anomaly of the Moon, in radians, given time tdb_c expressed in TDB Julian centuries since J2000.

delaunay_anomaly_sun(m::IERSModel, tdb_c::Number)

Compute the mean anomaly of the Sun, in radians, given time tdb_c expressed in TDB Julian centuries since J2000.

delaunay_longitude_diff(m::IERSModel, tdb_c::Number)

Compute the difference between the longitude of the Moon and the longitude of the Moon's node, in radians, given time tdb_c expressed in TDB Julian centuries since J2000.

delaunay_elongation_moon(m::IERSModel, tdb_c::Number)

Compute the mean elongation of the Moon from the Sun, in radians, given time tdb_c expressed in TDB Julian centuries since J2000.

delaunay_longitude_node(m::IERSModel, tdb_c::Number)

Compute the longitude of the mean ascending node of the lunar orbit on th ecliptic, measured from the mean equinox of date, in radians, given time tdb_c expressed in TDB Julian centuries since J2000.

PlanetaryArgs

Container holding the planetary arguments of the Nutation Theory.

Fields

• λ_Me – Mercury's mean heliocentric longitude, in radians.
• λ_Ve – Venus's mean heliocentric longitude, in radians.
• λ_Ea – Earth's mean heliocentric longitude, in radians.
• λ_Ma – Mars's mean heliocentric longitude, in radians.
• λ_Ju – Jupiter's mean heliocentric longitude, in radians.
• λ_Sa – Saturn's mean heliocentric longitude, in radians.
• λ_Ur – Uranus's mean heliocentric longitude, in radians.
• λ_Ne – Neptune's mean heliocentric longitude, in radians.
• pₐ – General precession in longitude, in radians.

pa_mercury(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Mercury in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_venus(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Venus in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_earth(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Earth in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_mars(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Mars in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_jupiter(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Jupiter in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_saturn(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Saturn in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_uranus(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Uranus in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

pa_neptune(m::IERSModel, tdb_c::Number)

Return the mean heliocentric longitude of Neptune in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

paprecession(m::IERSModel, tdbc::Number)

Return the general accumulated precession in longitude pₐ in radians, at time tdb_c expressed in TDB Julian centuries since J2000.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 36
• ERFA software library

fw2xy(ϵ::Number, ψ::Number, γ::Number, φ::Number)

Compute the CIP X and Y coordinates from Fukushima-Williams bias-precession-nutation angles, in radians.

References

• Wallace P. T. and Capitaine N. (2006), Precession-nutation procedures consistent with IAU 2006 resolutions, DOI: 10.1051/0004-6361:20065897

fw_angles(m::IERS2010, tt_c::Number)

Compute the precession angles, γ, ϕ, ψ, ϵ in radians, according to the IAU 2006 Fukushima-Williams 4-angle formulation at time tt_c expressed in TT Julian centuries since J2000.

References

• Luzum, B. and Petit G. (2012), The IERS Conventions (2010), IERS Technical Note No. 36
• Wallace P. T. and Capitaine N. (2006), Precession-nutation procedures consistent with IAU 2006 resolutions, DOI: 10.1051/0004-6361:20065897
• ERFA library

fw_matrix(γ, ϕ, ψ, ε)

Form a rotation matrix given the Fukushima-Williams angles, expressed in radians.

The present function can construct three different matrices depending on which angles are supplied as arguments:

• NPB: To obtain the Nutation-Precession-Bias (NPB) matrix, generate the four standard FW precession angles (̄γ, ̄ϕ, ̄ψ, ϵₐ) then generate the nutation components Δψ and Δϵ and add them to ̄ψ, ϵₐ. Finally, call the present functions using those four angles as arguments.

• PB: To obtain the Precession-Bias matrix, generate the four standard FW precession angles and call the present function.

• B: To obtain the frame bias matrix, generate the four standard FW precession angles at date J2000.0 and call this function.

The remaining nutation-only and precession only matrices can be obtained by combining these three appropriately.

References

• Wallace P. T. and Capitaine N. (2006), Precession-nutation procedures consistent with IAU 2006 resolutions, DOI: 10.1051/0004-6361:20065897
• ERFA library

NutationCorrections

Container to hold the nutation corrections and celestial pole offsets associated to a given IERS model (e.g., 2000A)

Fields

• δX, δY: Celestial pole offsets referred to the model IAU2000A (rad).
• δΔψ, δΔϵ: Nutation corrections in longitude and obliquity (rad)

See also

See also EOPData.

NutCorrectionsInterpolator

Container to store the interpolators for the nutation corrections and celestial pole offsets associated to a given IERS model.

See also

See also EOPInterpolator

EOPData{T}

EOP Data container. Data is parameterised by time expressed in Terrestrial Time (TT) days.

Fields

• filename : File where the EOP data are stored.
• days_UTC: UTC Julian days since J2000.
• cent_TT : TT Julian centuries since J2000.
• UT1_TT: UT1 minus TT offset, in seconds.
• LOD: Length of day offset (s).
• xp, yp: Polar motion with respect to the crust (rad).
• nut1996, nut2003, nut2006: nutation and CIP corrections.

EOPInterpolator

Container to store the interpolators for the loaded EOP data.

IERS_EOP

Earth Orientation Parameters (EOP) interpolators.

See also

See also eop_load_data! and EOPInterpolator.

IERS_EOP_DATA

Earth Orientation Parameters Data.

See also

See also EOPData.

eop_read_data(filename)

Read Earth Orientation Parameters (EOP) from a dedicated JSMD .eop.dat file.

eop_set_data!(m::IERSModel, filename)

Set Earth Orientation Parameters (EOP) to be used for frames transformations from a JSMD .eop.dat file, given a reference model m.

eop_write_data(data, output_filename)

Write the EOP data stored in the matrix data to a dedicated JSMD .eop.dat file.

See also

See also eop_generate_from_csv and eop_generate_from_txt.

δnut_to_δcip(m::IERSModel, t::Number, δΔψ::Number, δΔϵ::Number)

Convert nutation corrections in longitude δΔψ and obliquity δΔϵ to CIP corrections δX, δY at time t expressed in TT Julian centuries since J2000 for model m. All input and output EOP are given in radians.

References

• IERS Technical Note No. 36
• Paris IERS observatory FTP server (UAI2000 package).

See also

See also δcip_to_δnut.

δcip_to_δnut(m::IERSModel, t::Number, δX::Number, δY::Number)

Convert CIP corrections δX, δY to nutation corrections in longitude δΔψ and obliquity δΔϵ to at time t expressed in TT Julian centuries since J2000 for model m. All input and output EOP are given in radians.

References

• IERS Technical Note No. 36
• Paris IERS observatory FTP server (UAI2000 package).

See also

See also δnut_to_δcip.

eop_δΔψ(m::IERSModel, tt_c::Number)

Interpolate and retrieve the EOP nutation correction in longitude δΔψ, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_δΔϵ, eop_δX and eop_δY.

eop_δΔϵ(m::IERSModel, tt_c::Number)

Interpolate and retrieve the EOP nutation correction in obliquity δΔϵ, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_δΔψ, eop_δX and eop_δY.

eop_δX(m::IERSModel, tt_c::Number)

Interpolate and retrieve the CIP δX correction, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_δΔψ, eop_δΔϵ and eop_δY.

eop_δY(m::IERSModel, tt_c::Number)

Interpolate and retrieve the CIP δY correction, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_δΔψ, eop_δΔϵ and eop_δX.

eop_xp(m::IERSModel, tt_c::Number)

Interpolate and retrieve the pole xₚ coordinate, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_yp.

eop_yp(m::IERSModel, tt_c::Number)

Interpolate and retrieve the pole yₚ coordinate, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

See also

See also eop_xp.

eop_lod(m::IERSModel, tt_c::Number)

Interpolate and retrieve the length of day LOD offset, in seconds, at time tt_c expressed in TT Julian centuries since J2000 for the IERS convention m.

offset_tt2ut1(tt_s::Number)

Return the TT-to-UT1 offset, in seconds, at tt_s expressed in TT seconds since J2000.

PoissonSeries

This container stores the non-polynomial part of a Poisson series, i.e., the sine and cosine coefficients and the Delaunay's and Planetary arguments of the nutation theory multipliers.

NutationDataParser <: PoissonDataParser

Parser for nutation-like data, in which the orders of the different coefficients are stored on separate columns, e.g., in and out of phase.

Fields

• ncols: number of columns
• c_dargs: first column of the Delaunay's arguments
• c_pargs: first column of the planetary arguments
• c_sin: column with the sine terms
• c_cos: column with the cosine terms
• linePattern: regex expression to parse the relevant data lines

CIODataParser <: PoissonDataParser

Parser for CIO-like data, in which the orders of the different coefficients are separated by a specific line header in the form of " j = 0 Nb of terms = 1306".

Fields

• ncols: number of columns
• c_dargs: first column of the Delaunay's arguments
• c_pargs: first column of the planetary arguments
• c_sin: column with the sine terms
• c_cos: column with the cosine terms
• linePattern: regex expression to parse the relevant data lines

parse_iers_constants(filename::String, parser::PoissonDataParser)

Retrieve the Poisson series within filename with the configuration of parser.

generate_iers_file(filename::String, constant_name::Symbol, constant_data)

Generate or append the data in constant_data to filename as a variable named constant_name.

cio_locator(m::IERSModel, tt_c::Number, x::Number, y::Number)

Compute the CIO locator s, in radians, following the IERS Conventions m at time tt_c, expressed in TT Julian centuries since J2000, given the CIP coordinates x and y.

References

• Capitaine N. and Wallace P. T. (2008), Concise CIO based precession-nutation formulations
• IERS Technical Note No. 21
• IERS Technical Note No. 32
• IERS Technical Note No. 36

See also

See also iers_cip_motion, cip_xy and cip_xys.

equation_equinoxes(m::IERSModel, tt_c::Number, δΔψ::Number = 0)

Compute the Equation of the Equinoxes, in radians, according to the IERS Conventions m, at time tt_c expressed as TT Julian centuries since J2000. An optional EOP correction for the nutation in longitude can be passed via δΔψ.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 32
• IERS Technical Note No. 36

See also

See also iers_obliquity, iers_nutation_comp and eeq_complementary.

eeq_complementary(m::IERSModel, tt_c::Number)

Compute the complementary terms of the equation of the equinoxes, in radians, associated to the IERS Conventions m, at time tt_c expressed in TT Julian centuries since J2000.

References

• IAU Resolution C7, Recommendation 3 (1994)
• IERS Technical Note No. 21
• IERS Technical Note No. 32
• IERS Technical Note No. 36

npb2xy(A::AbstractMatrix)

Retrieve the CIP X and Y coordinates from the nutation-precession-bias matrix, in radians.

References

• Wallace P. T. and Capitaine N. (2006), Precession-nutation procedures consistent with IAU 2006 resolutions, DOI: 10.1051/0004-6361:20065897

precession_angles_rot3(m::IERSModel, tt_c::Number)

Return the equatorial precession angles zₐ, θₐ, ζₐ, in radians, at time tt_c expressed in TT Julian centuries since J2000 for the 3-rotations precession series initially used by Newcomb and Lieske.

References

• Lieske J. H. et al, (1977), Expression for the Precession Quantities Based upon the IAU (1976) System of Astronomical Constants.
• Capitained N. 2003b et al., Expressions for IAU 2000 precession quantities.
• Hilton J. L. et al., (2006), Report of the International Astronomical Union Division I Working

Group on Precession and the Ecliptic.

• IERS Technical Note No. 21
• IERS Technical Note No. 32
• IERS Technical Note No. 36

See also

See also iers_precession and precession_angles_rot4

precession_angles_rot4(m::IERSModel, tt_c::Number)

Return the precession angles ϵ₀, ψₐ, ωₐ, χₐ, in radians, at time tt_c expressed in TT Julian centuries since J2000 required for the canonical 4-rotations precession series.

References

• IERS Technical Note No. 21
• IERS Technical Note No. 32
• IERS Technical Note No. 36

See also

See also iers_precession and precession_angles_rot4

tio_locator(m::IERSModel, tt_c::Number)

Compute the TIO locator s' at date, positioning the Terrestrial Intermediate Origin on the equator of the Celestial Intermediate Pole (CIP) at time tt_c expressed as TT Julian centuries since J2000.

This function approximates the unpredictable motion of the TIO locator s' with its secular drift of ~0.47 μas/century.

References

• IERS Technical Note No. 36
• Lambert, S. and Bizouard C. (2002), Positioning the Terrestrial Ephemeris Origin in the Terrestrial Reference Frame, DOI: 10.1051/0004-6361:20021139

xys2m(x::Number, y::Number, s::Number)

Compute the GCRF-to-CIRF matrix given the CIP x, y' coordinates and the CIO locators`, all in radians.

References

• Wallace P. T. and Capitaine N. (2006), Precession-nutation procedures consistent with IAU 2006 resolutions, DOI: 10.1051/0004-6361:20065897
• ERFA library