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