Jules Verne Voyager: IAU Gazetteer

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IAU Gazetteer Index:


For more information about our Voyager map tool, contact:   Lou Estey   (louunavco.org)
Last modified: 21 Oct 2014



Overview     Voyager can be used to place feature names from the International Astronomical Union (IAU) gazetteer on maps of most worlds supported with Voyager. The IAU gazetteer menu options can be found in the [Features:] menu below the [--IAU gazetteer--] heading. The menu options for any world may vary over time as we refine the organization of the different feature types (see gazetteer descriptor terms of the feature types). All IAU currently approved names in the gazetteer are made available via Voyager; obsolete or dropped names are not.

Currently we are doing a periodic manual query using the USGS's gazetteer Advanced Nomenclature Search. Feature names in the gazetteer that have non-ASCII UTF-8 characters have those characters expanded into the closest GMT equivalent using GMT's Standard+ font set so that the names shown in Voyager images, if appropriate, should contain the correct diacritical marks.

The lettering size for a feature usually depends on the size of the feature, as given in the gazetteer, compared to the size of the world: the larger the feature, the larger the lettering. There are exceptions to this, such as the volcanic eruptive centers on Io, which are given a large lettering size.

 


Caveats     The following worlds have no features listed in the IAU gazetteer:

  • Earth — not covered by the IAU
  • the jovian planets (i.e. Jupiter, Saturn, Uranus, Neptune)
  • Pluto and its moons — no named features yet

IAU approved names for impact craters are for all other worlds except Jupiter's Io. Craters that have non-zero diameters listed in the gazetteer will have an outline for the crater computed based on the center latitude and longitude of the crater and the non-zero diameter. For craters listed with a diameter of zero, no outlines are computed. The following moons have no non-zero crater diameters listed in the gazetteer:

  • Jupiter's Amalthea
  • Saturn's Janus
  • Saturn's Epimetheus
  • Saturn's Hyperion (not yet a world explorable in Voyager)
  • Uranus's Puck (not yet a world explorable in Voyager)
  • Neptune's Triton
  • Neptune's Proteus

and therefore crater diameters on Amalthea, Janus, Epimetheus, Triton, and Proteus have been estimated for Voyager.

The following moons have gazetteer values of latitude = 0° and longitude = 0° = 360° for the center of all craters:

  • Saturn's Janus
  • Saturn's Epimetheus
  • Uranus's Puck (not yet a world explorable in Voyager)
  • Neptune's Proteus

and therefore the craters positions on Janus, Epimetheus, and Proteus have been estimated for Voyager.

The positions of all gazetteer feature names and impact crater outlines are based entirely from the information given in the gazetteer. The user will probably notice that in many cases there are slight offsets of the names or crater outlines from the corresponding image in the texture underlay image being used. Some of the possibilities for the offsets are:

  • the resolution of the feature center position given in the gazetteer lacks sufficient precision and/or sufficient accuracy
  • systematic offsets in the control grids for establishing positions in either the gazetteer datasets or the texture underlay images
  • the world (usually a small moon) is sufficiently irregular in shape such that the map projections being used in Voyager are insufficient to adequately render — in a precise geographical sense — the texture underlay image

All features listed in the gazetteer descriptor terms of the feature types are available through Voyager, except:

  • Venus: astrum, astra (AS)
  • Venus: reticulum, reticula (RT)
  • Jupiter's Europa: lenticula, lenticulae (LE)

— currently there are no named features of these types listed in the gazetteer.

And, for completeness, the following worlds have named features in the IAU gazetteer but are not yet viewable via Voyager:

  • any asteroid
  • Jupiter's Thebe
  • Saturn's Hyperion
  • Uranus's Puck

 


Comments, questions, problems about Jules Verne Voyager? Send mail to   Lou Estey   (louunavco.org)


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Jules Verne Voyager: IAU Gazetteer last modified on Tue, 21 Oct 2014 19:00 UTC
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