The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences. Vol. XXXVII. Part B7. Beijing 2008
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regions were continuously increasing and it is 179
(163 countries and 16 regions) as of April 30, 2008
(Figure. 1).
Figure 1 Number of participating countries and
regions (As of April 30, 2008)
3. ISCGM
International Steering Committee for Global Mapping
(ISCGM) was established in 1996. The primary
purpose of ISCGM is to examine measures that
concerned national, regional and international
organizations can take to foster the development of
Global Mapping in order to facilitate the
implementation of global agreements and conventions
for environmental protection as well as the mitigation
of natural disasters and to encourage economic growth
within the context of sustainable development. The
Committee consists of 20 members from the
representatives of national mapping organizations and
regional geographic information organizations in the
world except for the chair of ISCGM. Currently
ISCGM is chaired by Professor D. R. F. Taylor of
Carlton University, Canada. Geographical Survey
Institute (GSI), Japan has been working as its
secretariat since its establishment. ISCGM holds
meeting basically once a year and makes or updates
the specification of the Global Map and strategies to
promote data development, cooperation between
participants, use of the Global Map and other all
issues concerning the project.
The Global Map is a digital data set with the scale of 1
to 1 million or 1km resolution. It is composed of 8
layers, namely Boundaries, Drainage, Transportation,
Population centers, Elevation, Land cover, Land use
and Vegetations (Figure.2). First four layers are vector
data and latter four layers are raster images.
ITRF94 coordinate systems are used for the reference
coordinate system. GRS80 ellipsoid will be adopted to
represent the position of spatial objects in longitude
and latitude.
Regarding accuracy of the Global Map, followings are
described in the latest specification (version 1.3).
Absolute horizontal and vertical accuracy will vary by
location according to the source data.
Boundaries Drainage
Transportation Population centers
Elevation Land cover
Land use Vegetation
Figure 2 Layers of Global Map
4. Specifications of the Global Map