PIMAP AS A TOOL FOR CARTOGRAPHIC REPRESENTATION OF THE
"CATALOG OF LARGE MARTIAN IMPACT CRATERS"
S. Gehrke1, R. Koehring1, N.G. Barlow2
1 - Technische Universitaet Berlin, Geodesy and
Geoinformation Science, Berlin, Germany
2 - Northern Arizona University, Department of Physics and
Astronomy, Flagstaff, Arizona
stephan@igg.tu-berlin.de
The cartographic software package Planetary Image Mapper (PIMap) has been
developed for the generation of the Topographic
Image Map Mars 1:200,000. This large-scale map series is the cartographic
standard product of the Mars Express
mission, covering the Martian surface in 10,372 individual sheets. Each sheet
is based on High Resolution Stereo Camera (HRSC) images
and Digital Terrain Models for contour line derivation; it is supplemented
with graticules, topographic names (craters, mountains, valleys, etc.), map
titles, and further marginal information. The entire map content can be
generated and/or compiled using PIMap.
The Catalog of Large Martian Impact Craters
(henceforth Catalog) provides
information on 42,283 craters with minimum diameters of 5 km, such as, size,
shape, preservation, morphology, and ejecta properties. Compared to this, a
rather small number, 922 craters of all diameters, has been given names so far.
While the latter craters are labeled in various maps, the Catalog data are not represented in almost all cases except for few
special products. However, the large-scale Topographic Image Map Mars 1:200,000 series
allows for the integration of such a huge data set; once the ongoing revision
of the Catalog is completed (version
2.0), crater IDs will be included.
In order to
automate this part of map generation, PIMap is currently upgraded. Thus, the Catalog has to be matched with the USGS Gazetteer of Planetary Nomenclature,
which provides names and locations of all natural surface features for all
celestial bodies and, therefore, is the current basis for labeling in PIMap.
Technically, the entire information of both data bases is merged and mirrored
into a system of C++ classes. Based on the respective class “MarsCrater”, impact craters can be
labeled in topographic maps with their names and/or Catalog IDs, which are composed of latitude and longitude. With
regard to automation of thematic mapping it is conceivable to integrate, e.g.,
crater outlines, depths, or central peak heights in the map surface and,
depending on the user’s definitions, to give additional information in tabular
form within the legend.
In
conclusion, additional benefit of the new Topographic Image Map Mars 1:200,000 series results from becoming a cartographic representation of the
Catalog, i.e. the provision of the
scientific community with the link between appearances and locations of impact
craters and a huge set of further information. Beyond the generation of
standard map sheets, the cartographic software package PIMap can be used as
general visualization tool of the Catalog.