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EPN2020-RI

 

EUROPLANET2020 Research Infrastructure 

H2020-INFRAIA-2014-2015 

Grant agreement no: 654208

 

Document: VESPA-WP11-2-016-TN-v0.4(40)

 

 

 

 

Planetary Coordinate Systems

 

 

 

Date:  

 

Start date of project: 01 September  2015

 Duration: 48 Months

Responsible WP Leader: Stéphane Erard

 

Project co-funded by the European Union's Horizon 2020 research and innovation programme

Dissemination level

PU

Public

  •  

PP

Restricted to other programme participants (including the Commission Service)

  •  

RE

Restricted to a group specified by the consortium (including the Commission Services)

  •  

CO

Confidential, only for members of the consortium (excluding the Commission Services)

  •  

Project Number

654208

Project Title

EPN2020 - RI

Project Duration

48 months: 01 September 2015 – 30 August 2019

Document Number

WP11-task2--v0.4

Delivery date

Title of Document

Planetary Coordinate Systems

Contributing Work package (s)

WP11

Dissemination level

PU

Author (s)

Stéphane Erard, Baptiste Cecconi

Abstract:  The goal of this document is to define the description of Coordinate Systems used in the EPN-TAP protocol to access and retrieve Solar System data.

 

 

 

Document history (to be deleted before submission to Commission)

Date

Version

Editor

Change

Status

24/02/2012

0.1

Stéphane Erard

First Draft, extracted from EPN-Tap document V0.20

 DRAFT

27/02/2012

0.2

Stéphane Erard

Names update

 DRAFT

27/09/2013

0.3

Stéphane Erard , Baptiste Cecconi, Vincent Génot

Inclusion of various inputs

DRAFT

0.4

Added Space Physics frames, Jupiter related frames, SPICE frames, Galilean Moon frames (Section 2.8, 2.9, 2.10, 2.11)

 DRAFT

 

Table of Contents


Reference documents

To be included:

Other inputs to be included:

  • Chiara's comments, 7/2014
  • IMPEx / 3Dview frames doc, 9/2013
  • IAU Celes Mech Comm suggestion for historical frames (~ 10/2015)
  • Unified Planetary Coordinates - is it from USGS? Seems coupled to site: spatialreference.org

Acronym list

  • EPNCore Set of core parameters from EPN-DM, mandatory for EPN-TAP compatibility
  • EPN-TAP Specific protocol to access Planetary Science data in Europlanet-VO
  • EPN-DM Specific Data Model to describe Planetary Science data in Europlanet-VO
  • epn_core Name of table / view of a database which contains the EPN-TAP parameters. Required for EPN-TAP compatibility
  • IVOA International Virtual Observatory Alliance
  • IPDA International Planetary Data Alliance
  • PDAP (Planetary Data Access Protocol) Protocol to access planetary data space archives, developed and maintained by IPDA.
  • TAP (Table Access Protocol) One of the protocols developed by IVOA to access astronomical data.
  • ObsTAP TAP protocol applied to the Observation Data Model of IVOA
  • ObsCore set of core parameters from the Observation Data Model of IVOA
  • ADQL (Astronomical Data Query Language)

1 - Introduction

The EPN-TAP protocol is directly derived from IVOA’s TAP [RD3], a simple protocol to access data organized in tables, here adapted for Planetary Science data. EPN-TAP and its implicit Data Model EPNcore are described in [RD1]. A more comprehensive Data Model for Planetary Science is also available [RD2].  

In the EPN-TAP protocol, the data files are described in a table named epn_core by a set of mandatory parameters. The spatial_frame_type parameter provides the general “flavor” of the coordinate system, and can have the following values: celestial, body, cartesian, cylindrical, spherical, healpix. This parameter defines the nature of the 3 spatial coordinates (named c1,c2,c3).

When using some values of the spatial_frame_type parameter, the spatial_origin and spatial_coordinate_description parameters allow the data provider to specify the exact coordinate system used in the data set (including altitude). The system in use is known by the data provider, and the parameters are essentially intended to provide this information to the user for comparison with other data sets. In the future, this information could be used to perform automatic coordinate conversions.

The present document lists possible values for these parameters. The values listed here are adapted from the IAU Working Group on Cartographic Coordinates and Rotational Elements reports [RD5], the Space-Time Coordinates (STC) document from IVOA [RD4], the PDS standard reference, chap. 2 [RD6], and various references mentioned in the text. All values in the epn_core table should be provided in lower cases; all longitudes are expected to range from 0° to 360° eastward.

2 - Coordinate systems

2.1 Native coordinates

Data are projected in a frame related to the instrument or acquisition process.

Typical examples include: X/Y coordinates for a camera, X/time coordinates for an imaging spectrometer.

 

Possible situation:

spatial_frame_type = cartesian

spatial_coordinate_description = native

Are Spice instrument-frame names acceptable?

 

Practically, it means that data products are provided in a native instrument frame, and therefore are not spatially registered – they are not searchable on a coordinate basis in general.

 

2.2 Astronomical / telescopic coordinates

This situation is identified by:

spatial_frame_type = celestial

This provides 2 angles + 1 optional distance counted from the origin.

 

 

It is assumed that horizontal, ecliptic and galactic coordinates are provided with no explicit mention of epoch (which can be retrieved from the date of observation if need be).

The STC [RD4] distinguishes 3 types of equatorial systems:

 

FK4

Fundamental Katalog, system 4; Besselian

Requires Equinox; default B1950.0 Left-handed in spherical coordinates

FK5

Fundamental Katalog, system 5; Julian

Requires Equinox; default J2000.0 Left-handed in spherical coordinates

ICRS

International Celestial Reference System

 (based on radio sources) - Requires Equinox?

 

The reference position is provided through the spatial_origin parameter.

Values of interest from the STC [RD4] (table 1) are:

 

Reference Position

Description

Comments

GEOCENTER

Center of the Earth

 

BARYCENTER

Center of the solar system barycenter

 

HELIOCENTER

Center of the Sun

 

TOPOCENTER

“Local”; in most cases this will mean: the location of the telescope

 

EMBARYCENTER

Earth-Moon barycenter

 

MOON

Center of the Moon

 

MERCURY

Center of Mercury

 

VENUS

Center of Venus

 

MARS

Center of Mars

 

JUPITER

Center of Jupiter

 

SATURN

Center of Saturn

 

URANUS

Center of Uranus

 

NEPTUNE

Center of Neptune

 

PLUTO

Center of Pluto

 

RELOCATABLE

Relocatable center; for simulations

Only to be used for spatial coordinates

UNKNOWNRefPos

Unknown reference position

Only to be used as a last resort.
The client is responsible for assigning a suitable default

 

Can all value(s) for spacecraft, planetary landers, and orbital telescopes (with moving origin) be accessed through TOPOCENTER, or RELOCATABLE? — PDS3 uses a SPACECRAFT value.

+ Can an ephemeris file be provided for moving locations?

2.3 Solid bodies

This situation is identified by:

spatial_frame_type = body

Provides 2 angles + 1 optional distance (not necessarily from body center, therefore not consistent with the STC).

Coordinate systems may differ by the assumed shape of the body, its rotational elements, the location of the prime meridian, the control point network in use, and the definition of latitudes.

 

Body fixed reference frames:

Frames are defined through shape / rotational elements in [RD5]  

            http://astrogeology.usgs.gov/Page/groups/name/IAU-WGCCRE

+ reference geoid models for the Earth?

 

Standard planetary coordinate systems and reference ellipsoids are listed here (IAU doc –older systems are not included):

            http://planetarynames.wr.usgs.gov/TargetCoordinates

 

Control networks used are important to mention for high-resolution imaging.

Information about Control Networks can be found here (USGS):

            http://astrogeology.usgs.gov/maps/control-networks

The values mentioned in this and other sources are:

Moon:

ULCN1994— Unified Lunar Control Network (1994)

CLCN — related to Clementine Basemap, 1997

ULCN2004 — Unified ULCN1994 and CLCN, 2004

LOLCN — related to Lunar Orbiter images, 2004

ULCN2005 — Unified Lunar Control Network revised, 2005 (?)

LOLA2011 – Lunar Orbiter, 2011

Mars:

Control Networks are referred to the Digital Image Model first using them.

MDIM — Original Viking mosaics

MDIM2.0 — Mars Digital Image Mosaic (MDIM) 2.0 control network

MDIM2.1 — Mars control network tied to the MOLA Digital Elevation Model

http://www.isprs.org/proceedings/XXXV/congress/comm4/papers/464.pdf

 

Actual map projections are listed here (ie, list of existing surface maps):            http://www.mapaplanet.org/explorer/help/data_set.html

 

+ see http://www.lpi.usra.edu/meetings/lpsc2006/pdf/1931.pdf

for possible use in OGC

 

Coordinate systems may be planetocentric (defined relative to a vector passing by the center of mass) or planetographic (defined relative to the local horizontal plane), resulting in different latitudes if the body is not spherical.

Coordinate systems may be defined as east-handed or west-handed. In the IAU 2000 standard, planetocentric systems must be east-handed for planets and satellites. In any case, the epn_core table must contain a version with eastward longitudes ranging from 0° to 360°, in order to handle EPN-TAP queries without ambiguity.

 

Possible nomenclature:

Target + IAU + year of introduction?            => Mars_IAU2000

Does not tell if this is planetocentric/graphic?

Spice names look like IAU_Mars (= always the latest version implied)

 

References for small bodies

According to IAU standards, small bodies are all considered prograde and their north pole is defined accordingly.

Coordinate system name should state shape model/prime meridian in use?

 

The STC document distinguishes 2 options related to the meaning of the third coordinate:

To be introduced through the spatial_origin parameter??

 

GEO_C

Geographic (geocentric) coordinates: longitude, latitude, geocentric distance

GEO_D

Geodetic coordinates: longitude, latitude, elevation

 

In many cases the surface is used as origin, e.g., in atmospheric databases – this corresponds to the geodetic option above.

+ Need different origin for planetographic coordinates?

 

2.4 Giant planets

This situation is identified by:

spatial_frame_type = body

Provides 2 angles + 1 optional distance (from body center, for consistency with STC?? TBC)

 

STC distinguishes between planetographic and planetocentric:

 

 

Planetocentric

Planetographic

 

Jupiter_C_III

Jupiter_G_III

 

Saturn_C_III

Saturn_G_III

 

Uranus_C_III

Uranus_G_III

 

Neptune_C_III

Neptune_G_III

 

In the PDS3 standard reference there is only one value for each planet in the coordinate_system_ID keyword:

    "-JUPSYS3", "-SATSYS3", "-URNSYS3" + VSO

2.5 Plasma / dynamic coordinates

This situation may correspond to

spatial_frame_type = cartesian or spherical

 

From STC document:

 

MAG

Geomagnetic coordinates

See F&H (2002)

GSE

Geocentric Solar Ecliptic coordinates

See F&H (2002)

GSM

Geocentric Solar Magnetic coordinates

See F&H (2002)

SM

Solar Magnetic coordinates

See F&H (2002)

HGC

Heliographic coordinates (Carrington)

See Explanatory Supplement, Section 7.2 Thompson (2006), Section 2.2

HGS

Heliographic coordinates (Stonyhurst)

See Explanatory Supplement, Section 7.2 Thompson (2006), Section 2.2

HEEQ

Heliographic Earth Equatorial coordinates

See F&H (2002); related to Heliographic (Stonyhurst), see Thompson (2006), Section 2.1

HRTN

Heliocentric Radial- Tangential-Normal coordinates

See F&H (2002)

HPC

Helioprojective Cartesian coordinates

See Thompson (2006), Section 4.1, 2- or 3-dimensional (angular coordinates); left- handed

HPR

Helioprojective Polar coordinates

See Thompson (2006), Section 4.1, 2- dimensional (angular coordinates); left- handed

HCC

Heliocentric Cartesian coordinates

See Thompson (2006), Section 3.1 (linear coordinates); right-handed

HGI

Heliographic Inertial coordinates

See F&H (2002)

 

2.6 Magnetospheric coordinates

This situation may correspond to

spatial_frame_type = cartesian or spherical

 

Three types of reference frames are used:

-      planetocentric solar magnetic (X towards Sun; Z towards planetary magnetic North pole). Only exist when the body has an intrinsic magnetic field.

-      planetocentric solar equatorial (X towards Sun; Z perpendicular to the equator of the planet, towards the planetary North pole)

-      planetocentric solar ecliptic (X towards the Sun; Z perpendicular to ecliptic plane, in the northern celestial hemisphere)

Each of them is centered on the planet barycenter. Y axis is completing the orthogonal direct reference frames.

 

Planet

Name

Acronym

 

Mercury

Hermian Solar Ecliptic

Hermian Solar Magnetic

Hermian Solar Equatorial

HSE

HSM

HSQ

 

Venus

Venus Solar Ecliptic

Venus Solar Equatorial

VSE

VSQ

 

Earth

Geocentric Solar Ecliptic

Geocentric Solar Equatorial

Geocentric Solar Magnetic

GSE

GSQ

GSM

 

Mars

Martian Solar Ecliptic

Martian Solar Equatorial

MSE

MSQ

 

Jupiter

Jovian Solar Ecliptic

Jovian Solar Equatorial

Jovian Solar Magnetic

JSE

JSQ

JSM

 

[see F&H 2002, section 4.3.1]

Saturn

Kronian Solar Ecliptic

Kronian Solar Equatorial

Kronian Solar Magnetic

KSE

KSQ

KSM

 

 

Uranus

Uranian Solar Ecliptic

Uranian Solar Equatorial

Uranian Solar Magnetic

USE

USQ

USM

 

Neptune

Neptunian Solar Ecliptic

Neptunian Solar Equatorial

Neptunian Solar Magnetic

NSE

NSQ

NSM

 

 

2.7 Landers/rovers coordinates

This specific situation is expected to be correctly described in the PDS3/4 reference, TBC.

2.8 Solar-terrestrial interactions

Derived from a SPASE document compiling various sources.

AcronymNameDescriptionReference

CGM

Corrected GeoMagnetic

A coordinate system from a spatial point with GEO radial distance and geomagnetic latitude and longitude, follow the epoch-appropriate IGRF/DGRF model field vector through to the point where the field line crosses the geomagnetic dipole equatorial plane. Then trace the dipole magnetic field vector Earthward from that point on the equatorial plane, in the same hemisphere as the original point, until the initial radial distance is reached. Designate the dipole latitude and longitude at that point as the CGM latitude and longitude of the original point.

(1,2,11)
CARCarrington

A coordinate system which is centered at the Sun and is "fixed" with respect to the synodic rotation rate; the mean synodic value is about 27.2753 days. The Astronomical Almanac gives a value for Carrington longitude of 349.03 degrees at 0000 UT on 1 January 1995.

(1,11)
DMDipole Meridian

A coordinate system centered at the observation point. Z axis is parallel to the Earth's dipole axis, positive northward. X is in the plane defined by Z and the line linking the observation point with the Earth's center. Y is positive eastward.

(1,3,11)
GEI (or GCI)Geocentric Equatorial Inertial

A coordinate system where the Z axis is along Earth's spin vector, positive northward. X axis points towards the first point of Aries (from the Earth towards the Sun at the vernal equinox).

(1,3,4,5,8,9,10,11)
GEOGeographic - geocentric corotatingA coordinate system where the Z axis is along Earth's spin vector, positive northward. X axis lies in Greenwich meridian, positive towards Greenwich.(1,3,4,5,8,9,11)
GSEGeocentric Solar EclipticA coordinate system where the X axis is from Earth to Sun. Z axis is normal to the ecliptic, positive northward. (1,3,4,5,8,9,10,11)
GSEQGeocentric Solar EquatorialA coordinate system where the X axis is from Earth to Sun. Y axis is parallel to solar equatorial plane. Z axis is positive northward.(1,3,9)
GSM

Geocentric Solar Magnetospheric

A coordinate system where the X axis is from Earth to Sun, Z axis is northward in a plane containing the X axis and the geomagnetic dipole axis.(1,3,4,5,9,10,11)
HAEHeliocentric Aries EclipticA coordinate system where the Z axis is normal to the ecliptic plane, positive northward. X axis is positive towards the first point of Aries (from Earth to Sun at vernal equinox). Same as SE below. (1,5,8,11,12)
HCCHeliocentric CartesianA 3-D orthonormal coordinate system that is primarily intended to specify with two dimensions a point on the solar disk. The Z axis points toward the observer. The Y axis lies in the plane defined by the solar spin vector and the Z axis, positive northward. The X axis is perpendicular to the Y and Z axes, positive toward solar west. Standard representation for this system is via the point's x and y values, expressed either as physical distances or as fractions of the solar disk radius.(1)
HCDHeliocentric of Date
(11)
HCIHeliographic Carrington Inertial
(1,8,11,12)
HCR

Heliocentric Radial

A 3-D orthonormal coordinate system that is primarily intended to specify with two dimensions a point on the solar disk. The Z axis points toward the observer. The Y axis lies in the plane defined by the solar spin vector and the Z axis, positive northward. The X axis is perpendicular to the Y and Z axes, positive toward solar west. Standard representation for this system is via the point's distance rho from the Z axis [Rho = SQRT(x**2 + y**2)] and its phase angle psi measured counterclockwise from the +Y axis [psi = arctan (-y/x)](1)
HEEHeliocentric Earth EclipticA coordinate system where the Z axis is normal to the ecliptic plane, positive northward. X axis points from Sun to Earth.(1,5,8,11)
HEEQ

Heliocentric Earth Equatorial

A coordinate system where the Z axis is normal to the solar equatorial plane, positive northward. X axis is generally Earthward in the plane defined by the Z axis and the Sun-Earth direction.(1,5,8,11)
HG (or HGC)HeliographicA heliocentric rotating coordinate system where the Z axis is normal to the solar equatorial plane, positive northward. X, Y axes rotate with a 25.38 day period. The zero longitude (X axis) is defined as the longitude that passed through the ascending node of the solar equator on the ecliptic plane on 1 January, 1854 at 12 UT.(1,6,11,12)
HGIHeliographic Inertial

A heliocentric coordinate system where the Z axis is normal to the solar equatorial plane, positive northward. X axis is along the intersection line between solar equatorial and ecliptic planes. The X axis was positive at SE longitude of 74.367 deg on Jan 1, 1900. (See SE below.)

(1,6)
HPCHelioprojective CartesianA 3-D orthonormal (left-handed) coordinate system that is primarily intended to specify with two dimensions a point on the solar disk. The Z axis points from the observer to the center of the solar disk. The Y axis lies in the plane defined by the solar spin vector and the Z axis, positive northward. The X axis is perpendicular to the Y and Z axes, positive toward solar west. Given as the distance between the observer and the center of the solar disk, the standard representation of an (x,y) point on the solar disk is via the point's longitude angle [arctan (x/d)] and latitude angle [arctan y/d].(1)
HPRHelioprojective RadialA 3-D orthonormal (left-handed) coordinate system that is primarily intended to specify with two dimensions a point on the solar disk. The Z axis points from the observer to the center of the solar disk. The Y axis lies in the plane defined by the solar spin vector and the Z axis, positive northward. The X axis is perpendicular to the Y and Z axes, positive toward solar west. Given as the distance between the observer and the center of the solar disk, the standard representation for this system of an (x,y) point on the solar disk is via the point's latitude angle theta {= arctan [SQRT(x**2 + y**2)]/d]} or equivalent declination parameter delta (= theta - 90 deg), and its phase angle psi as measured counter- clockwise from the +Y axis [psi = arctan (-y/x)].(1)
HSHeliocentric SolarX = Intersection between solar equator and solar central meridian as seen from Earth. Z = North Pole of solar rotation axis.(10)
HSEaHeliocentric Solar Ecliptic (Inertial)X = First point of Aries (Vernal Equinox, i.e. to the Sun from Earth in the first day of Spring). Z = Ecliptic North Pole(10)
HSEbHeliocentric Solar Ecliptic (Earth Oriented)X = Sun-Earth Line. Z = Ecliptic North Pole(10)
J2000J2000An astronomical coordinate system which uses the mean equator and equinox of Julian date 2451545.0 TT (Terrestrial Time), or January 1, 2000, noon TT. (aka J2000) to define a celestial reference frame.(1)
LGMLocal GeomagneticA coordinate system used mainly for Earth surface or near Earth surface magnetic field data. X axis northward from observation point in a geographic meridian. Z axis downward towards Earth's center. In this system, H (total horizontal component) = SQRT (Bx^2 + By^2) and D (declination angle) = arctan (By/Bx)(1)
MAGGeomagnetic - geocentricZ axis is parallel to the geomagnetic dipole axis, positive north. X is in the plane defined by the Z axis and the Earth's rotation axis. If N is a unit vector from the Earth's center to the north geographic pole, the signs of the X and Y axes are given by Y = N x Z, X = Y x Z.(1,3,4,5,11)
MFAMagnetic Field AlignedA coordinate system spacecraft-centered system with Z in the direction of the ambient magnetic field vector. X is in the plane defined by Z and the spacecraft-Sun line, positive sunward.(1,3)
RTNRadial Tangential NormalTypically centered at a spacecraft. Used for IMF and plasma V vectors. R (radial) axis is radially away from the Sun, T (tangential) axis is normal to the plane formed by R and the Sun's spin vector, positive in the direction of planetary motion. N (normal) is R x T.(1,10,11,12)
SCSpacecraftA coordinate system defined by the spacecraft geometry and/or spin. Often has Z axis parallel to spacecraft spin vector. X and Y axes may or may not corotate with the spacecraft. See SR and SR2 below.(1)
SESolar Ecliptic A heliocentric coordinate system where the Z axis is normal to the ecliptic plane, positive northward. X axis is positive towards the first point of Aries (from Earth to Sun at vernal equinox). Same as HAE above.(1,6)
SM

Solar Magnetic

A geocentric coordinate system where the Z axis is northward along Earth's dipole axis, X axis is in plane of z axis and Earth-Sun line, positive sunward.(1,3,4,5,9,11)
SRSpin ReferenceA special case of a Spacecraft (SC) coordinate system for a spinning spacecraft. Z is parallel to the spacecraft spin vector. X and Y rotate with the spacecraft.(1,3)
SR2

Spin Reference 2

A special case of a Spacecraft (SC) coordinate system for a spinning spacecraft. Z is parallel to the spacecraft spin vector. X is in the plane defined by Z and the spacecraft-Sun line, positive sunward.(1,3)
SSESpacecraft Solar EclipticA coordinate system used for deep space spacecraft, for example Helios. - X axis from spacecraft to Sun. Z axis normal to ecliptic plane, positive northward. Note: Angle between normals to ecliptic and to Helios orbit plane ~ 0.25 deg.(1,11)
SSE_LSelenocentric Solar EclipticThe X axis points from the center of the Earth's moon to the sun, the Z axis is normal to the ecliptic plane, positive northward. And the Y axis completes the right-handed set of axes.(1)
SCOPSpacecraft Orbit PlaneA coordinate system where X lies in the plane normal to and in the direction of motion of the spacecraft, Z is normal to this plane and Y completes the triad in a right-handed coordinate system.(1)
VDHVertical Dusk Horizontal system

The V-axis is the outwards local vertical, to the point of observation. The H-axis is parallel to the horizontal local plane, positive to the North. The V-H plane is a geographic meridian plane. The D-axis is azimuthal, eastwards.
As DM system, this system is a local coordinate system, which is dependent of the position of the point of observation from the Earth.

(3)
WGS84World Geodetic System 1984The World Geodetic System (WGS) defines a reference frame for the earth, for use in geodesy and navigation. The WGS84 uses the zero meridian as defined by the Bureau International de l'Heure.(1,9)


[1] http://www.spase-group.org/data/search.jsp?term=Coordinate+System+Name&style=entry&scope=dictionary&version=2.2.0

[2] http://omniweb.gsfc.nasa.gov/vitmo/cgmm_des.html 

[3] http://cdpp2.cnes.fr/cdpp/data/documents/PLAS-LO-ROCOTLIB-00428-CET/00428.pdf and software libraries in IDL (tar) or Fortran (tar)

[4] C.T. Russell, (1971) "Geophysical Coordinate Transformations", Cosmic. Electrodyn. 2, 184-196. URL: http://www-ssc.igpp.ucla.edu/personnel/russell/papers/gct1.html

[5] M.A. Hapgood, (1992) "Space Physics Coordinate Transformations: A User Guide", Planet. Space Sci. 40, 711-717.
M.A. Hapgood, (1997) "Corrigendum to Space Physics Coordinate Transformations: A User Guide", Planet. Space Sci. 45, 1047. 

[6] http://cohoweb.gsfc.nasa.gov/helios/coor_des.html

[7] http://sspg1.bnsc.rl.ac.uk/SEG/Coordinates/refs.htm

[8] http://stereo-ssc.nascom.nasa.gov/coordinates_explanation.shtml

[9] http://www.spenvis.oma.be/help/background/coortran/coortran.html

[10] http://www.srl.caltech.edu/ACE/ASC/coordinate_systems.html

[11] M.Fraenz and D.Harper, Heliospheric Coordinate Systems, Planet. Space Sci., 50, 217-233 (Feb 2002). URL: http://www.mps.mpg.de/homes/fraenz/systems/

[12] http://helio-vo.eu/documents/public/HELIO_Coordinates_100322.pdf

[13] Thompson, W. T. Coordinate systems for solar image data. A&A 449, 791–803 (2006). http://www.aanda.org/10.1051/0004-6361:20054262



2.9 Jovian Systems

from Fraenz and Harper (2002):

AbbrevNameDescription
JUP_IJovian System I

Mean atmospheric equatorial rotation. +Z -axis: pole of rotation. Rotation speed: 877.900 degree/day

JUP_IIJovian System IIMean atmospheric polar rotation. +Z -axis: pole of rotation. Rotation speed: 870.270 degree/day
JUP_IIIJovian System IIIMagnetospheric rotation. +Z -axis: pole of rotation. Rotation speed: 870.53 degree/day
JUP_III_sunJovian System III, fix Sun Line+Z-axis: pole of rotation. +Y-axis: cross-product of +Z-axis and vector (Jupiter–Sun).
JUP_DJovian Magnetic Dipole System 

+Z-axis: dipole axis defined by its System III latitude and longitude: lat_D = (90° − 9.8°); lambda_D = 200°

+X -axis: intersection of System III prime meridian and magnetic equator.


Jovian Centrifugal System

+Z -axis: centrifugal axis defined by its System III latitude and longitude: lat_C = (90° − 7.0°); lambda_C = 200°.

+X -axis: intersection of System III prime meridian and centrifugal equator.


Magnetic Dipole System  x Sun line+Z -axis: dipole axis.
+Y -axis: cross-product of +Z -axis and vector (Jupiter–Sun).

Magnetic Dipole r-th-ph   System+X-axis: vector (Jupiter-S=C)
+Z-axis: cross product of (dipole axis) and +X-axis.
This system depends on the S=C-position.


2.10 SPICE Built-in Frames

From SPICE Ref Manual:

List of IAU-Body-Fixed reference frames: IAU_ADRASTEA, IAU_AMALTHEA, IAU_ANANKE, IAU_ARIEL, IAU_ATLAS, IAU_BELINDA, IAU_BENNU, IAU_BIANCA, IAU_BORRELLY, IAU_CALLIRRHOE, IAU_CALLISTO, IAU_CALYPSO, IAU_CARME, IAU_CERES, IAU_CHALDENE, IAU_CHARON, IAU_CORDELIA, IAU_CRESSIDA, IAU_DAVIDA, IAU_DEIMOS, IAU_DESDEMONA, IAU_DESPINA, IAU_DIONE, IAU_EARTH, IAU_ELARA, IAU_ENCELADUS, IAU_EPIMETHEUS, IAU_ERINOME, IAU_EROS, IAU_EUROPA, IAU_GALATEA, IAU_GANYMEDE, IAU_GASPRA, IAU_HARPALYKE, IAU_HELENE, IAU_HIMALIA, IAU_HYPERION, IAU_IAPETUS, IAU_IDA, IAU_IO, IAU_IOCASTE, IAU_ISONOE, IAU_ITOKAWA, IAU_JANUS, IAU_JULIET, IAU_JUPITER, IAU_KALYKE, IAU_LARISSA, IAU_LEDA, IAU_LUTETIA, IAU_LYSITHEA, IAU_MAGACLITE, IAU_MARS, IAU_MERCURY, IAU_METIS, IAU_MIMAS, IAU_MIRANDA, IAU_MOON, IAU_NAIAD, IAU_NEPTUNE, IAU_NEREID, IAU_OBERON, IAU_OPHELIA, IAU_PALLAS, IAU_PAN, IAU_PANDORA, IAU_PASIPHAE, IAU_PHOBOS, IAU_PHOEBE, IAU_PLUTO, IAU_PORTIA, IAU_PRAXIDIKE, IAU_PROMETHEUS, IAU_PROTEUS, IAU_PUCK, IAU_RHEA, IAU_ROSALIND, IAU_SATURN, IAU_SINOPE, IAU_STEINS, IAU_SUN, IAU_TAYGETE, IAU_TELESTO, IAU_TEMPEL_1, IAU_TETHYS, IAU_THALASSA, IAU_THEBE, IAU_THEMISTO, IAU_TITAN, IAU_TITANIA, IAU_TRITON, IAU_UMBRIEL, IAU_URANUS, IAU_VENUS, IAU_VESTA.

2.11 Galilean Moon Frames

Two coordinate systems are provided:

  • SPRH (Satellite centered planetocentric, right-handed),
  • PhiO (Satellite centered inertial Phi-Omega coordinates),

Distances from the satellites are measured in satellite radii. The radii values used for the various satellites are listed in the following Table:

MoonRadius (km)
Amalthea86.2
Io1818
Europa1560
Ganymede2634
Callisto2409

Satellite centered coordinate systems names are preceded by the first letter in the name of the satellite, in order to indicate which satellite is used as the center. In order words, PhiO coordinates are called EPhiO at Europa and CPhiO at Callisto

SPRH (Satellite centered planetocentric, right-handed)

This coordinate system is the basic J2000 definition of planetocentric coordinates, as applied to each of the satellites. In it's Cartesian form the coordinate system has its Z-axis along the satellite axis of rotation positive in the direction of angular momentum, the X-axis in the equatorial plane in the direction of the prime meridian, with the Y-axis completing the right-handed set. The coordinate system rotates with the satellite (body-fixed).

All of the SPRH data in this data set are based on the International Astronomical Union (IAU) definitions of the satellite axes orientations and rotation rates from the Report of the IAU/IAG/COSPAR Working Group on Cartographic Coordinates and Rotational Elements of the Planets and Satellites: 1994 [IAU1994]. The specific orbit elements for each satellite are summarized in the following Table:

SatelliteAxis orientation J2000Prime Meridian*
Right AscensionDeclinationConstantRate
Amalthea268.05+64.49231.67+722.6314560
Io268.05+64.50200.39+203.4889538
Europa268.08+64.5135.67+101.3747235
Ganymede268.20+64.5744.04+50.3176081
Callisto268.72+64.83259.73+21.5710715

* PM = const + rate*d where d is days after the J2000 epoch.

PhiO (Satellite centered inertial Phi-Omega coordinates)

The basis vectors of the inertial Phi-Omega coordinate systems are defined at an epoch time that is set at the time of spacecraft closest approach to the satellite. The X-direction is defined to be in the direction of corotation, at the center of the satellite at the epoch time (System III Phi direction [DESSLER1983]). The Z-axis is defined to be orthogonal to the X direction such that the X-Z plane contains the Jupiter spin axis (Omega), positive in the direction of angular momentum. The Y-axis is defined to complete the right-handed set. Since the jovian satellites all lie very close to the jovian equatorial plane, it is often convenient to visualize this coordinate system as follows: X lies in the direction of plasma flow, Y points towards Jupiter, and Z points 'up'.

2.12 Anything else?

Comets maybe?

 

 

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5 Comments

  1. we are starting to have planetary coordinates in the official OGC Resolver (opengis.net) see https://github.com/planetserver/planetary-crs there are some naming issues, but the above could be helpful, e.g. Stéphane Erard Trent Hare Chiara Marmo

    1. Yes, we have to check this. 

      By the way, we will restart activity on that topic with Steve Joy (NASA/PDS/PPI and UCLA), who is now co-chair of the IVOA Solar System Interest Group. Our goal is to:

      1. Consolidate the list of reference frames used in Solar and Planetary sciences 
      2. Check external resources (e.g., the OGC resolver or the NAIF/SPICE frames) and manage to remain up-to-date with those resources
      3. Update (when needed) the IVOA/STC2 list of StdRefFrames values.
      4. (longer term) describe the Solar and Planetary references frames with IVOA/STC2, and/or map between NAIF/SPICE and/or OGC descriptions of the reference frames. 


  2. The IAU WGCCRE proposes (2018) to refer to historical / past version of IAU frames by using the bibcode or DOI of the relevant IAU WGCCRE report; they also propose to use this convention for frames not defined by the WG but publised/used in research papers.

    Plus, codes such as IAU2000 are also commonly used in a generic sense, including in GDAL (this actually refers to a set of resolutions taken that year and affecting the standards, e.g. planetocentric conventions have eastward longitudes)

    There is an IAU sotfware lib handling projections and computations: http://www.iausofa.org/

  3. Note for future: make sure to check planetocentric/graphic and heliocentric/graphic definitions (are they consistent different?)

  4. Note: current Map-a-Planet link " http://www.mapaplanet.org/explorer/help/data_set.html" has been retired. The new site can be linked to: https://www.mapaplanet.org/

    I am still digesting this page - lots of into.

    Note: Jean-Christophe Malapert (CNES), for the new 2015 WKT definitions, revamped whole code base, called create_IAU2000.py, which generates these. This code is still in review. The code now does a much better job at differentiating ocentric/ographic latitude systems and longitude direction (East/West - depends on the rotation direction). Now whether many applications (e.g. existing GIS apps) will easily support West is doubtful. We are hopeful that with updates to Proj"5" in GDAL (currently under way), planetary projections will be better supported (in regards to the latitude systems).

    updated code: https://github.com/USGS-Astrogeology/GDAL_scripts/blob/master/OGC_IAU2000_WKT_v2/Source_Python/create_IAU2000.py

    table which lists NAIF codes and IAU 2015 standards as published in the 2018 paper which the code uses: https://github.com/USGS-Astrogeology/GDAL_scripts/blob/master/OGC_IAU2000_WKT_v2/naifcodes_radii_m_wAsteroids_IAU2015.csv

    2018 IAU paper (for 2015 codes): https://github.com/USGS-Astrogeology/GDAL_scripts/blob/master/OGC_IAU2000_WKT_v2/Docs/IAU2015_Archinaletal2018.pdf 

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