vant
oils,
y as
GIS
ling
pact
GIS
into
Ver,
GIS
nost
it of
| of
ined
nore
ome
land
hese
nt to
| be
tive
ition
adily
d to
such
from
RS)
‚ the
data,
k to
the
IDN
odes
SDA
orld
antly
the
mes
fast
]Sers
995;
ving
jonal
SDIS
will provide a two-way link between the EOS and its users. It
will assure timely processing of RS and collateral data,
generation of standardized EOS products, serve as an
interactive source of information on EOS data, products and
programs, and provide links with the national and
international EOS Centers. Although the total EOS’ budget,
at present about US $ 7 billion, is still being discussed,
EOSDIS is expected to cost about one third of this total. Such
a significant funding is indicative of the importance that
NASA assigns to effective management and dissemination of
EOS data, derived products and information.
In order to further increase the effectivness of management of
geospatial information, Canada and the United States have
initiated the establishment of spatial data infrastructures, the
Canadian Spatial Data Infrastructure (CSDI) and National
Spatial Data Infrastructure (NSDI) respectively. Their
objective is to enhance and promote the interoperability
between the geospatial data archives. Their successful
implementation requires an effective network of geospatial
data archives; adherance to standards for spatial data formats,
quality and electronic transfers (section 2.9); development of
appropriate regulatory and institutional policies, as well as
promotional activities. It is expected that these developments
will eventually lead to the establishment of Global Spatial
Data Infrastructure (GSDI).
2.9 Standards for Geospatial Data and Products
The increasing number of countries operating EO satellites
and thus generating a wide range of RS data and derived
products, as well as fast growing electronic transfers of such
data, make necessary the adoption of international standards.
The international standards are particularly important for
regional and global projects, when large geospatial datasets,
including RS data and derived products, originating in many
countries, have to be transformed to a common database,
integrated and processed in GIS, and the results transmitted
back to participating countries. These tasks are best achieved
under a broader framework of developing standards for all
geospatial data formats, to assure their compatibility.
Recognizing the growing need for the development of
standards for geospatial data and derived products, the
International Organization for Standardization (ISO)
established a Technical Committee for Geographic
Information / Geomatics, the ISO/TC-211, in 1994. At present,
there are 23 member countries and 13 countries in an
observing capacity, participating in the work of the ISO/TC-
211. All the countries operating EO satellites are among the
member countries. It is expected that the existing national and
international standards for geospatial data formats, most
notably the NATO Digital Geographic Exchange Standard
(DIGEST) for geographic digital data in vector formats and
DIGEST-Image for data in raster formats, will be gradually
harmonized with and incorporated into the standards to be
developed by the ISO/TC-211. (Ostensen, 1995).
Another important series of international standards, which is
relevant to geospatial data and products, is the ISO 9000
series of standards on quality assurance. Strict compliance
with these standards by the regional and global mapping and
monitoring programs will guarantee their quality, and thus
facilitate the international acceptability of their products.
417
3. NEXT GENERATION OF EO SATELLITES
FOR REGIONAL AND GLOBAL
MAPPING AND MONITORING
3.1 Earth Observing System (EOS)
Remote sensing capacities for continuous environmental
monitoring and land cover mapping at regional and global
levels will be significantly strengthened when the NASA - led
international program, the Earth Observing System (EOS),
starts the deployment of a new generation of EO satellites in
1998. The EOS is the centerpiece of NASA’s program
“Mission to Planet Earth”, which aims at gaining a broad
understanding of the Earth as a system. It is based on
systematic, long-term Earth observations from space
platforms, complemented by ground observations in selected
sites. The overall objective of EOS is to support the Mission to
Planet Earth with RS data from EO satellites, relevant to
worldwide assessments and forecasts of impacts of global
change. EOS is the most important and comprehensive attempt
to close the wide gaps in geospatial information about the
Earth natural resources. The timely availability of such
information, to be generated by EOS, is a prerequisite to
sustainable development.
The EOS space segment will consist of up to 17 EO satellites.
Its final configuration, sensor payloads, and the extent of
international participation are still being discussed. Landsat-7,
to be launched in 1998, will be part of EOS. (Section 3.3) It is
expected that EOS, when fully deployed, will generate over 2
terabytes of data daily. In order to be able to process, archive
and disseminate such a huge volume of data to scientists
around the world, NASA initiated development of EOS Data
Information System (EOSDIS). (Section 2.8).
One of the key RS sensor systems for environmental
monitoring, developed for EOS, is the Moderate Resolution
Imaging Spectroradiometer (MODIS). It will record images of
the Earth’s surface in 32 spectral bands, with ground
resolution of 250 m for 2 bands (red and near-IR), 500 m for 5
bands (visible and near-IR) and 1 km for 25 bands (ranging
from the blue part of spectrum to thermal-IR). MODIS is of
particular interest to the regional and global environmental
monitoring and land cover mapping programs because it will
provide a complete global coverage with 250m - 1km ground
resolution, and 32 spectral bands every 2 days. Its spectral
bands were selected to enable better spectral discrimination of
land cover classes, compared to the NOAA/AVHRR system.
Furthermore, MODIS data will have significantly improved
geometric rectification and radiometric calibration. The size of
MODIS scenes will be 2000km x 2000km. MODIS will be
included in the RS payload of several EOS satellites, starting
with AM-1, which is scheduled for launch in 1998. (Asrar &
Dozier, 1994; Justice et al, 1994; NASA/GSFC, 1996;
Townshend et al., 1991).
3.2 NOAA/TIROS Follow-on
A follow-on to the NOAA/TIROS successful series of polar-
orbiting meteorological satellites with the AVHRR RS sensor
system will be the National Polar Orbiting Environmental
Satellite System, operated jointly by NOAA and the U.S.
Department of Defence. It will consist of three spacecrafts,
orbiting in conjunction. Currently, NOAA and the U.S.
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
