nd 
2g, 
ea 
or 
al 
3 
Ist 
- existing maps (ex. DEM) 
- remote sensing (ex. land cover) 
- ground measurement (ex. runoff) 
- census (ex. population) 
- other global datasets (ex. evapotranspiration) 
In the early attempt of the production of global 
datasets, main sources were existing maps. 
Examples are the global DEM, ETOPOS, by 
Margaret Edwards and one-degree global land 
cover data by M.F. Wilson and Anne 
Henderson-Sellers. Satellite remote sensing is a 
powerful tool to produce global datasets. There 
are many programs to launch satellite for the 
purpose of developing global datasets of land 
cover, biomass, ozone, precipitation, ocean 
chlorophyll, snow and ice. They are ADEOS, 
ADEOS-II, TRMM, EOS-AMI and EOS-PMI, 
SPOT-4. Some variables such as river runoff 
are collected by ground measurement, and many 
other variables such as land cover and 
precipitation needs ground measurement for the 
ground truth. Most socio-economic data is 
collected by census. Since various global 
datasets have become available, a dataset of new 
variable can be estimated and derived from the 
existing datasets. Such an example is global 
dataset of 30-minute evapotranspiration (Ahn 
1994). 
Most global datasets in the early stage have an 
unit area from one degree to thirty minute grid, 
while the present tendency is one kilometer(or 
thirty second) grid. This is the same resolution 
as NOAA AVHRR data. Land cover data and 
DEM are being produced with this resolution by 
IGBP-DIS and GLOBE(Global Land One km 
Base Elevation) committee, respectively. 
Who contribute to develop global datasets and 
global database? Dataset producers, dataset 
distributors, and database planners do. Dataset 
producers are individual researchers or a group 
of researchers. There are many dataset 
producers in different fields, different academic 
societies, and different countries. On the 
contrast, there are a few dataset distributors 
which are: 
- UNEP/GRID 
- NOAA/ National Geophysical Data Center, 
USA 
- Rutgers University, USA 
- Earth Observing System Data and Information 
System (EOSDIS) / Distributed Active Archive 
Centers (DAAC), USA 
These organizations collect and distribute 
various global datasets, while there are some 
organizations which distributes a specific global 
dataset. The Global Runoff Data Centre of 
Germany is one of them. 
A database planner mentioned here is a group of 
people who pursuit the development of better 
and useful global database of key environmental 
variables. Such groups are: 
- International academic society such as ISPRS, 
International Geographical Union (IGU), and 
International Cartographic Association (ICA) 
- International organizations such as United 
Nations Environment Programme (UNEP) and 
United Nations Development Programme 
(UNDP) 
- International projects initiated by national 
proposal such as Global Mapping by Japan and 
Earth Map by USA 
3. ISPRS WG IV/6 
The Working Group IV/6 on "GIS and Expert 
Systems for Global Environmental Databases" 
was established at the ISPRS Washington 
Congress in 1992. The Working Group has put 
emphasis on studies of global datasets/database 
of key environmental variables. The activities 
by the Working Group from 1992 were: 
- Two international workshops 
- Survey of national and regional geographic 
data bases 
The International Workshop on Global GIS was 
held at Tokyo, Japan from August 24-25, 1993. 
The workshop was jointly organized with 
855 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996