UCDList_1-3_RFM < IVOA

<span style="color: darkgreen;"> </span>

---+ Request for Modification for the UCD List v1.3 - from May 2017 to Feb 2018
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This page is proposed in the new process for UCDs update discussed at the Interop meeting in Shanghai in May 2017.

As mentionned in the Maintenance for UCD specification we are adopting the following process. When a new UCD term seems necessary to ibe included in the UCD list, a record describing the request for addition can be expressed as followed : new term proposed, rationale, example of usage, etc , as show in the <span style="color: #630000; font-size: 17.29px; font-weight: 700; text-indent: -24px;">Proposed RFMs </span>section below<span style="background-color: transparent;">.</span>

The term is then discussed within the maintenance committee and the semantics working group and answers from the maintenance committee is given within 1 month.

Every 6 months the list of proposed changes are examined by the TCG and the validated changes are ingested in the new version of Endorsed Note for the UCD1+ list of terms.

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<span style="color: #630000; font-size: 17.290000915527344px; font-weight: bold; background-color: transparent;">Accepted RFMs</span>

<strong><span style="color: darkgreen;">addition </span></strong>Q | *phys.electCharge* | Electric charge

<strong><span style="color: darkgreen;">addition </span></strong>Q | *phys.current* | Electric current

<strong><span style="color: darkgreen;">addition </span></strong>Q | *phys.current.density* | Electric current density

<strong><span style="color: darkgreen;">addition </span></strong>Q<span style="background-color: transparent;"> | </span><span style="background-color: transparent;"> </span><span style="background-color: transparent;"> </span> *pos.incidenceAng* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">| Incidence angle of optical ray on an interface</span>

<span style="background-color: transparent;"> </span>

<strong><span style="color: darkgreen;">addition </span></strong><span style="background-color: transparent;">Q</span><span style="background-color: transparent;"> | </span><span style="background-color: transparent;"> </span><span style="background-color: transparent;"> </span> *pos.emergenceAng* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">| Emergence angle of optical ray on an interface</span>

<span style="background-color: transparent;"> </span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> </span><span style="background-color: transparent;"> </span>Q<span style="background-color: transparent;"> | </span> *pos.azimuth* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">| azimuthal angle in a generic reference plane</span>

<span style="background-color: transparent;"> </span><strong><span style="color: darkgreen;">addition</span></strong><span style="background-color: transparent;"> Q | *phys.reflectance* | Radiance factor (received radiance divided by input radiance)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong><span style="background-color: transparent;"> Q | </span><strong>phys.reflectance.bidirectiona</strong><span style="background-color: transparent;"><strong>l</strong> | Bidirectional reflectance</span></span>

<span style="background-color: transparent;"><span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *phys.reflectance.bidirectional.df* | Bidirectional reflectance distribution function</span></span>

<span style="background-color: transparent;"><span style="background-color: transparent;"> </span></span>

<strong><span style="color: darkgreen;">addition </span></strong><span style="background-color: transparent;">Q | *phys.reflectance.factor* | Reflectance normalized per direction cosine of incidence angle</span>

<span style="background-color: transparent;"><span style="color: darkgreen;"><strong>addition </strong>S</span><span style="background-color: transparent;"> | </span> *pos.cylindrical* |Related to cylindrical coordinates</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition </span></strong><span style="background-color: transparent;">Q |</span> *pos.cylindrical.r* | Radial distance from z-axis (cylindrical coordinates)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *pos.cylindrical.azi* | Azimuthal angle around z-axis (cylindrical coordinates)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *pos.cylindrical.z* | Height or altitude from reference plane (cylindrical coordinates)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> S | *pos.spherical* | Related to spherical coordinates</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *pos.spherical.r* | Radial distance or radius (spherical coordinates)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *pos.spherical.colat* |Polar or Colatitude angle (spherical coordinates)</span>

<span style="background-color: transparent;"><strong><span style="color: darkgreen;">addition</span></strong> Q | *pos.spherical.azi* | Azimuthal angle (spherical coordinates)</span>

<span style="background-color: transparent;"><span style="color: darkgreen;"> *addition* </span>Q | *pos.resolution* | Spatial linear resolution (not angular)</span>

<span style="color: darkgreen;"> *addition* </span>S | *pos.bodycentric* | Body-centric related coordinate

<span style="background-color: transparent;"> </span>

<span style="color: darkgreen;"> *addition* </span>S | *pos.bodygraphic* | Body-graphic related coordinate

<span style="color: darkgreen;"> *addition* </span>Q | *meta.checksum* | Numerical signature of digital data

<strong><span style="color: darkgreen;">addition </span></strong>Q |<strong> phys.polarization.coherency</strong> | Matrix of the correlation between components of an electromagnetic wave
<h3>
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<span style="font-weight: normal; background-color: transparent; font-size: 17.29px;">The terms discussed and proposed for endorsement by the TCG are described in the </span><span style="font-weight: normal; background-color: transparent; font-size: 17.29px;">EN-UCDlist-1.4-20180523 document ( in progress).</span>

<span style="font-variant-numeric: normal; font-variant-east-asian: normal; font-weight: normal; font-stretch: normal; font-size: 7pt; line-height: normal; font-family: "> </span>
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Rejected RFMs 
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<span style="font-weight: normal; background-color: transparent; font-size: 17.29px;">Terms not fully discussed and agreed on have been </span><span style="background-color: transparent; font-size: 17.29px;">postponed</span><span style="font-weight: normal; background-color: transparent; font-size: 17.29px;"> to the next iteration.</span>

<em style="color: #000000; font-family: arial, verdana, sans-serif; font-size: 13.65px;"><span style="background-color: transparent;"><span style="font-weight: 400;">pos.rotat</span><span style="font-weight: normal;">ion, pos.euleraAngle, pos.quaternion, ...</span></span></em>

<em style="color: #000000; font-family: arial, verdana, sans-serif; font-size: 13.65px;"><span style="background-color: transparent;"><span style="font-weight: normal;">pos.heliocentric, pos.heliographic, etc .. postponed for better understanding : should consider the possibility of combination with other existing UCD .</span></span></em>

Proposed RFMs
</h3>

Here are the proposed terms with their proposal , discussion part and the status of agreement for addition of a UCD term or modification.
---+++ Proposals from Solar and Planetary community ( B. Cecconi, S. Erard et al.)

---+++++ <span style="color: darkgreen;">Concept family : electric charge and current </span>

   * *Family* <span style="background-color: transparent;">: plasma environment</span>
   * *Proposal* <span style="background-color: transparent;">: </span> _phys.flux;phys.charge_
   * *Requires* <span style="background-color: transparent;">: phys.charge with definition : Electric charge and tag : Q</span>
   * *Answer:* <span style="background-color: transparent;"> we understood the need for two concepts : electric current density and electric charge proposal for update:</span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *phys.electCharge* | Electric charge <br /><strong><span style="color: darkgreen;">add</span></strong> Q | *phys.current* | Electric current<br /><strong><span style="color: darkgreen;">add</span></strong> Q | *phys.current.density* | Electric current density

   * *Status* <span style="background-color: transparent;">: inserted</span>
   * *Benefits* _: introduces phys.current; this definition is more focused on the requested concept --&gt; implies better assignment_
---+++++ <span style="color: darkgreen;">Concept family: Observation geometry ; Illumination conditions</span>

   * <span style="background-color: transparent;"> *Case:* </span> 
      * <span style="background-color: transparent;">Representation of the various angles : Explained in paper </span>https://doi.org/10.1016/j.pss.2015.06.004
      * <span style="background-color: transparent;">See figure attached </span>[[http://wiki.ivoa.net/internal/IVOA/UCDList_1-4_RFM/emergence_incidenceAngle.jpg][here]]
      * <span style="background-color: transparent;">theta_i = Incidence Angle, theta_e = Emergence Angle, alpha = Phase Angle </span>
      * <span style="background-color: transparent;">The angle phi (azimuth) is not required for illumination condition description (and we already have a UCD for this) </span> _from Baptiste Cecconi_
   * *Rationale:* <span style="background-color: transparent;"> -from B. Cecconi - 06 July 2017 - see semantics list for the email threads</span> 
      * <span style="background-color: transparent;">In planetary sciences ... our use cases are the following:</span>
      * <span style="background-color: transparent;">In EPNcore, the illumination conditions are search parameters, we have 6 separate columns for the min/max values of those 3 angles.</span>
      * <span style="background-color: transparent;">For planetary images or spectra, the product metadata must contain the observation geometry, and those 3 angles are to be there, altogether.</span>
---++++++ <span style="color: darkgreen;">Concept: Incidence angle</span>

   * <span style="background-color: transparent;"> *Proposal:* </span> _pos.incidenceAng_
   * <span style="background-color: transparent;"> *Requires:* </span> 
      * <span style="background-color: transparent;">definition : Incidence angle</span>
      * <span style="background-color: transparent;">tag : Q</span>
   * *preliminary answer proposed:* *pos.posAng.incidence* with definition : "Angle of incidence of a vector e.g illumination vector"
   * *Discussion:* There is a debate about this (S.Erard): incidence and emergence are physical angles of an optical ray on an interface / can be like pos.phaseAng; <span style="background-color: transparent;"> </span> then it could logically be hooked under pos directly , as pos.phaseAng
   * <strong>answer: </strong>This is understood that we deal here with generic optical angles. <span style="background-color: transparent;"> </span>
<span style="background-color: transparent;"> </span><strong><span style="color: darkgreen;">add </span></strong>Q<span style="background-color: transparent;"> | </span><span style="background-color: transparent;"> </span><span style="background-color: transparent;"> </span> *pos.incidenceAng* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> | Incidence angle of optical ray on an interface</span>
---++++++ <span style="color: darkgreen;">Concept: Emergence angle</span>

   * <span style="background-color: transparent;"> *proposal:* </span> _pos.emergenceAng_
   * <span style="background-color: transparent;"> *Requires:* </span> 
      * <span style="background-color: transparent;">definition : Emergence angle</span>
      * <span style="background-color: transparent;">tag : Q</span>
   * *Answer:* <span style="background-color: transparent;"> see discussion about _incidence angle_ </span>
<strong><span style="color: darkgreen;">add </span></strong><span style="background-color: transparent;">Q</span><span style="background-color: transparent;"> | </span><span style="background-color: transparent;"> </span><span style="background-color: transparent;"> </span> *pos.emergenceAng* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> | Emergence angle of optical ray on an interface</span>

<span style="color: darkgreen;"> </span>
---++++++ <span style="color: darkgreen;">Concept: Azimuth angle</span>

   * <span style="background-color: transparent; color: #000000;"> *Proposal:* </span><span style="background-color: transparent;"> </span> _pos.azimuthAng_
   * *Requires:* 
      * <span style="background-color: transparent;">definition : Azimuthal angle</span>
      * <span style="background-color: transparent;">tag : Q</span>
   * *Discussion:* azimuthal angle is already defined in the ucd tree by: 
      * <span style="background-color: transparent;"> _pos.az.azi_ exists but implies an alt-azimuthal ccordinate system.</span>
   * *Answer:* azimuth already means 'angle'. We select pos.azimuth instead of pos.azimuthalAng ( shorter and self explaining) <span style="background-color: transparent;"> </span>
<span style="background-color: transparent;"><strong><span style="color: darkgreen;">add</span></strong> </span><span style="background-color: transparent;"> </span>Q<span style="background-color: transparent;"> | </span> *pos.azimuth* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> | azimuthal angle in a generic reference plane</span>
---+++++ <span style="color: darkgreen;">Concept family: </span><span style="color: #006400;">spectroscopic measures</span>
---++++++ <span style="color: darkgreen;">Concept : radiance </span>

   * *Proposal:* definition of phot.radiance is not completely adequate. It<span style="background-color: transparent;"> should be </span> _radiant power from the source per unit area (of source) and unit solid angle_
   * *Discussion:* TBD
---++++++ <span style="color: darkgreen;">Concept : reflectance </span>

Reflectances are relative quantities comparing input radiance or flux to the observed radiance, with various adimensional nomalization, so that their units can't be used for decide which actual physical quantity is shared or plotted. As current<span style="background-color: transparent;"> spectral analysis tools are using UCDs to decide how to combine data from various sources, there is a need for high level descriptors to sort out the most obvious kinds of normalization of processing. Without this, comparisions between dataset may lead to meaningless results. </span>

   * <span style="background-color: transparent;"> *proposal:* </span> _phys.reflectance_ <span style="background-color: transparent;"> </span>
   * <span style="background-color: transparent;"> *rationale:* different from albedo, which is valid at a given wavelength or frequency. </span>
   * <span style="background-color: transparent;"> *definition:* This is a </span>radiance factor: observed radiance divided by input radiance. This quantity derives from the surface or interface properties.
   * <span style="background-color: transparent;"> *annotation master* : to check ; consequence : change definition to albedo and remove reflectance </span> 
      * <span style="background-color: transparent;"> | phys.albedo | Albedo or reflectance</span>
   * *Discussion:* it is preferable to add a new term
   * <span style="background-color: transparent;"> *Possible derived usage* : Radiance Factor : arith.factor;phys.reflectance</span>
   * <strong>Answer: </strong><span style="background-color: transparent;">the reflectance term is added.</span>
<strong><span style="color: darkgreen;">add</span></strong><span style="background-color: transparent;"> Q | *phys.reflectance* | Radiance factor (received radiance divided by input radiance)</span>

<span style="background-color: transparent;"> </span>
---

   * *Proposal:* _phys.reflectance.I_over_F_
   * *Rationale:* <span style="background-color: transparent;"> This a specific measured reflectance, which may include the thermal emission of the body. This is defined as the observed radiance, divided by the input illumination flux (solar flux for planetary bodies). No correction for the black body emission is done on this quantity. </span><span style="background-color: transparent;"> </span>
   * <span style="background-color: transparent;"> *Discussion:* open</span>
---
   * <span style="background-color: transparent;"> *Proposal:* </span> _phys.reflectance.bidirectional_
   * <span style="background-color: transparent;"> *Definition:* bidirectional reflectance </span> 
      * <span style="background-color: transparent;">tag : Q</span>
   * <strong>Discussion:</strong>The current accepted short name is _bidir_
   * *Answer:* add new term
<strong><span style="color: darkgreen;">add</span></strong><span style="background-color: transparent;"> Q | </span><strong>phys.reflectance.bidirectiona</strong><span style="background-color: transparent;"><strong>l</strong> | Bidirectional reflectance</span>
---
   * <span style="background-color: transparent;"> *Proposal:* </span> _phys.brdf_
   * <span style="background-color: transparent;"> *Definition:* </span> bidirectional reflectance distribution function 
      * <span style="background-color: transparent;">tag: Q</span>
   * *Discussion:* check if phys.reflectance.bidirectional;instr.det.psf would do ? 
      * no, this is specific to normalization
   * <span style="background-color: transparent;"> *Answer:* add new term (t</span>he current accepted short name is _BRDF_ )
<strong><span style="color: darkgreen;">add</span></strong> Q | *phys.reflectance.bidirectional.df* | Bidirectional reflectance distribution function
---

   * <span style="background-color: transparent;"> *Proposal:* </span> _phys.reflectance.factor_
   * <span style="background-color: transparent;"> *Definition:* reflectance normalized per direction cosine of incidence angle ??</span> 
      * <span style="background-color: transparent;">tag : Q</span>
   * *Answer:* add new term
<strong><span style="color: darkgreen;">add </span></strong><span style="background-color: transparent;">Q | *phys.reflectance.factor* | Reflectance normalized per direction cosine of incidence angle</span>

   * _NB : check relevance and possible ambiguity with radiance factor..._ 
      * <span style="background-color: transparent;">for normalized reflectance concept</span>
      * <span style="background-color: transparent;">proposal </span> *arith.ratio;phys.reflectance*
      * <span style="background-color: transparent;">definition : reflectance normalized per reflectance at one wavelength <hr /> </span>
---+++++ <span style="color: darkgreen;">Concept family: Coordinate frames</span>
---++++++ <span style="color: darkgreen;">Concept : Cylindrical coordinates</span>

   * *Proposal:* <span style="background-color: transparent;"> _pos.cylindrical_ </span>
   * *Rationale* : SSIG coordinates systems. No such coordinate branch in the UCD tree yet.
   * *Definition* : Cylindrical coordinates 
      * tag : S
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<span style="color: darkgreen;"><strong>add </strong>S</span><span style="background-color: transparent;"> |</span><strong>pos.cylindrical</strong> |Related to cylindrical coordinates
---

<strong><br /></strong>
   * *Proposal:* <span style="background-color: transparent;"> _pos.cylindrical.r_ </span>
   * Requires :pos.cylindrical
   * *Definition* : Cylindrical coordinate (radial distance from z-axis) 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add </span></strong><span style="background-color: transparent;">Q |</span> *pos.cylindrical.r* | Radial distance from z-axis (cylindrical coordinates)
---

   * *Proposal:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> _pos.cylindrical.th_ </span>
   * *Definition* <span style="background-color: transparent;"> : Cylindrical coordinate (Azimuthal angle around z-axis)</span> 
      * tag : Q
   * *Discussion* The conventions for the name of the angles varies : see <span style="background-color: transparent;">http://mathworld.wolfram.com/CylindricalCoordinates.html </span>prefered azi instead of th
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *pos.cylindrical.azi* | Azimuthal angle around z-axis (cylindrical coordinates)
---

   * *Proposal:* <span style="background-color: transparent;"> _pos.cylindrical.z_ </span>
   * *Definition* : Cylindrical coordinate (height from reference plane) 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *pos.cylindrical.z* | Height or altitude from reference plane (cylindrical coordinates)

<em><span style="white-space: pre;"> </span>NB: less ambiguous as for angle names</em>

<span style="color: darkgreen;"> </span>
---++++++ <span style="color: darkgreen;">Concept: Spherical Coordinates</span>

   * *Proposal:* <span style="background-color: transparent;"> _pos.spherical_ </span>
   * *Rationale*: not present in UCD tree definition : spherical coordinates 
      * tag : S
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add</span></strong> S | *pos.spherical* | Related to spherical coordinates
---

   * *Proposal:* _pos.spherical.r_
   * *Definition* : spherical coordinate (radial distance from origin) 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *pos.spherical.r* | Radial distance or radius (spherical coordinates)
---

   * <span style="background-color: transparent;"><span style="font-weight: bold; background-color: transparent;">Proposal: </span><span style="background-color: transparent;"> _pos.spherical.th_ </span></span>
   * *definition* : spherical coordinate (colatitude angle) 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
   * <span style="background-color: transparent;"> *Discussion:* _same as for cylindrical : various angle names depending on definitions ( http://mathworld.wolfram.com/SphericalCoordinates.html )_ </span>
   * <span style="background-color: transparent;"> _proposed to use the physical name for this angle : colatitude to avoid any notation dependency/ambiguity_ </span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *pos.spherical.colat* |Polar or Colatitude angle (spherical coordinates)
---

   * *Proposal:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">p<em>os.spherical.ph</em></span><span style="background-color: transparent;"> </span>
   * *definition* : spherical coordinate (Azimuth angle) 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add</span></strong> Q | *pos.spherical.azi* | Azimuthal angle (spherical coordinates)
---

<span style="background-color: transparent; color: darkgreen; font-size: 12.35px; font-weight: bold;">Concept : orbital parameters</span>

%Comment perifocal "src.orbital.periastron" exists but is slightly different<br />%Comment periapsis : check variation in meaning

   * *Proposal:* <span style="background-color: transparent;"> </span> _src.orbital.periapsis_
   * *Definition* <span style="background-color: transparent;">: minimal distance to the center of mass for an orbit</span> 
      * tag : P
   * *Answer* _discussion postponed not yet decided_
<span style="color: darkgreen;"> </span>
---++++++ <span style="color: darkgreen;">Concept : rotation params for 3D parameters</span>

*Discussion* _pos. is the right branch to hook these rotation concepts._

_pos.wcs exist for 2D transformation ;_

_pos.rotation will handle the 3D case --&gt; propose pos.rotation3d__

_Theses parameters will be used soon with real data ._
   * *Answer:* _We decide to delay the addition and will consider several examples_
---

   * *Proposal* <span style="background-color: transparent;">: </span><em><span style="background-color: transparent;">pos.rotatio</span><strong style="background-color: transparent;">n</strong></em><span style="background-color: transparent;"> </span>
   * *definition* <span style="background-color: transparent;"> : Relative to rotation </span> 
      * tag : S
   * *proposal*: <span style="background-color: transparent;">pos.rotation.eulerAngle</span>
   * *definition* <span style="background-color: transparent;"> : Euler angles vector </span> 
      * tag : V
   * *proposal* <span style="background-color: transparent;">: </span><span style="background-color: transparent;">pos.rotation.quaternion </span>
   * definition : rotation quaternion vector 
      * tag : V
   * *proposal:* <span style="background-color: transparent;">pos.rotation.matrix</span><span style="background-color: transparent;"> </span>
   * *definition* <span style="background-color: transparent;"> : rotation matrix</span> 
      * tag : V
   * *proposal* <span style="background-color: transparent;">: </span> *pos.rotation.axis*
   * *definition* <span style="background-color: transparent;"> : rotation axis vector</span> 
      * tag : V
---
---++++++ <span style="color: darkgreen;">Concept: spatial resolution</span>

   * *Proposal* <span style="background-color: transparent;">: </span><span style="background-color: transparent;"> _pos.resolution_ </span>
   * *Rationale* <span style="background-color: transparent;">: linear resolution on cartesian or linear spatial axis as opposed to angular resolution</span><span style="background-color: transparent;"> </span>
   * *Definition* <span style="background-color: transparent;"> : Spatial linear resolution (not angular)</span> 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<span style="color: darkgreen;"> *add* </span> Q | *pos.resolution* | Spatial linear resolution (not angular)
---

<br /><span style="color: #006400;">Concept: </span><span style="color: darkgreen; background-color: transparent; font-size: 12.35px; font-weight: bold;">heliocentric coordinates</span>

   * *Discussion* <span style="background-color: transparent;"> longitude and latitude can be expressed in the heliocentric coordinate system </span>
   * *Proposal* <span style="background-color: transparent;">: </span><span style="background-color: transparent; white-space: pre;"> </span><span style="background-color: transparent;">pos.bodyrc.lon;pos.heliocentric </span> <span style="background-color: transparent;"> </span><span style="background-color: transparent; white-space: pre;"> </span><span style="background-color: transparent;">pos.bodyrc.lat;pos.heliocentric </span>
% induced changes in assign tool: if heliocentric, or centric except geocentric , --&gt; not earth .... change token
   * *Decision* _: agreed to modify assigning tool - done_
   * *Discussion* _: In body-centric coordinates, longitudes are defined from sub-observer point, while body-graphic coordinates are defined from a standard body reference frame_
TODO: VESPA team to check consistency between heliocentric and planetocentric definitions
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<span style="color: darkgreen;"> *add* </span> S | *pos.bodycentric* | Body-centric related coordinate

<span style="color: darkgreen;"> *add* </span> S | *pos.bodygraphic* | Body-graphic related coordinate
---

---+++++ *Metadata branch*

<span style="color: #006400;"> </span>

<span style="color: #006400; background-color: transparent; font-size: 12.35px; font-weight: bold;">Concept: checksum</span>

   * *Proposal:* _meta.checksum_
   * *rationale* <span style="background-color: transparent;">: to check integrity of data</span>
   * *definition* : numerical signature of digital data 
      * tag : Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<span style="color: darkgreen;"> *add* </span> Q | *meta.checksum* | Numerical signature of digital data
---

<span style="color: #006400; background-color: transparent; font-size: 12.35px; font-weight: bold;">Concept: modification date of a dataset</span>
   * *proposal:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> _time.update_ </span>
   * *definition* <span style="background-color: transparent;">: modification date for a dataset</span>
   * <span style="background-color: transparent;"> *discussion* _:time.processing already exists and can be used here . only the definition of the ucd term to be modified_ </span>
_??? update of the definition in the UCD list_

---

<strong style="background-color: transparent; color: #630000; font-size: 14.3px;"><span style="color: darkgreen;">Other items</span></strong>
---++++++ <span style="color: darkgreen;">Concept: shape of planetary objects</span>

%this is used to represent the 3D shape of object: a 3D lattice
   * *proposal* <span style="background-color: transparent;">:</span> _phys.shape_
   * *definition* : 3D shape of an object 
      * tag : Q
   * *Rationale* <span style="background-color: transparent;"> : consider usage like phys.shape;meta.modelled for a 3D shape model, or </span>phys.shape;pos.bodyrc.alt for elevation or terrain model (distribution of altitude on top of a reference ellipsoid or geoid )
   * *Answer* _discussion: postponed until a real case is met_
---++++++ <span style="color: #630000; font-size: 12.350000381469727px; font-weight: bold; background-color: transparent;">Concept: spectral polarization data</span>

#concept :spatial matrix<br />rationale: helps to identify or characterize measurement type

   * *proposal* <span style="background-color: transparent;">: </span> _phys.polarization.coherenceMatrix_
   * *definition* <span style="background-color: transparent;">: coherence matrix of radio signals </span>
   * *rationale* <span style="background-color: transparent;"> phys.polarisation.coherenceMatrix:instr</span> 
      * tag:Q
   * *Answer:* <span style="background-color: transparent;"> </span><span style="background-color: transparent;"> </span><span style="background-color: transparent;">add new term</span>
<strong><span style="color: darkgreen;">add </span></strong>Q |<strong> phys.polarization.coherency</strong> | Matrix of the correlation between components of an electromagnetic wave

_NB: This will work for all electromagnetic signals and not only in radio regime_

_caveat: not compatible to instr branch in the UCD tree._
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* Set ALLOWTOPICRENAME = IVOA.TWikiAdminGroup<br />--&gt;

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This topic: IVOA > WebHome > IvoaSemantics > UCDList_1-3_RFM
Topic revision: r11 - 2019-10-07 - BaptisteCecconi