capacities nor the resources to undertake the extensive 
mapping and monitoring programs required to fill the 
geospatial information gaps. Yet, no country should be left out 
of the effort to achieve one of the most noble of our goals: to 
preserve the heritage of the earth’s natural resources and its 
healthy environment for future generations. (Kalensky, 1995). 
Since 1972, when the first civilian earth resources technology 
satellite (ERTS, later renamed Landsat) was launched by the 
National Aeronautics and Space Administration (NASA) of 
the United States, satellite remote sensing (RS) data have 
been increasingly used for land cover mapping, natural 
resources assessment and environmental monitoring 
worldwide. Growing networks of earth observation (EO) 
satellites and ground receiving stations provide unprecedented 
opportunities for the use of RS in the mapping and monitoring 
programs at the regional and global levels. Acquisition of RS 
data is not hindered by the remoteness of the area nor by its 
difficult accessibility, which is of particular importance for 
developing countries. (Cihlar et al., 1989; Estes et al., 1992; 
Ryerson & Lo, 1995). 
While natural resources assessment is typically conducted at 
the national level, there is a growing demand for land cover 
mapping and environmental monitoring at regional and global 
levels (Townshend et al, 1991). Effective measures for 
environmental protection, which is an essential requirement of 
sustainable development, can be best implemented at 
international levels. Eight selected regional and global 
programs, ongoing and planned, are briefly described in 
Section 4. Term “regional” in the context of this paper 
follows the United Nations terminology and is approximately 
synonymous with the term "continental". 
There is a considerable confusion in the scientific literature 
over the use of terms “land cover” and “land use”. The land 
cover characteristics interpreted from RS data represent a 
complex mixture of natural and anthropogenic ground classes 
(mapping units). They reflect not only the variations in natural 
vegetation, topography, soils, soil moisture and surface water 
bodies, but also the type and intensity of land use and land 
degradation. While each area on the earth’s surface can be 
identified by a unique land cover class, only areas used by 
humans can also be identified by land use classes. Although 
there is a link between the land cover and land use, not all 
land use types can be identified from RS data alone. 
Supplementary information, such as socio-economic, 
agronomic, climatic, etc., is required for the mapping of land 
use. In 1994, the United Nations Environment Programme 
(UNEP) and the Food and Agriculture Organization of the 
United Nations (FAO) started a joint project, the “Initiative on 
Standardisation of Land Use and Land Cover Classification 
Systems”, in order to clarify and settle this issue. 
The term “geomatics” is used in Canada, and increasingly by 
other countries, as an overall, encompassing term for 
disciplines concerned with surveying and mapping of the 
earth’s -surface. It includes the land surveying, topographic 
mapping, photogrammetry, remote sensing, cartography, 
global positioning systems and geographic information 
systems. Its use underlines stronger links between such 
disciplines, because of the increasing integration and 
processing of their data by geographic information systems, 
which requires harmonization of standards for quality and 
414 
formats of data and derived products, as well as compatibility 
of their databases. 
2. ADVANCED GEOMATICS TOOLS 
FOR REGIONAL AND GLOBAL 
MAPPING AND MONITORING 
Land cover mapping and environmental monitoring at regional 
and global levels have only recently become possible because 
of significant technological advances in geomatics. These 
advances include the growing operational uses of EO satellites 
with optical and microwave RS payloads, global positioning 
systems, geographic information systems, modernization of RS 
data archives, and establishment of electronic information 
networks, accompanied by development of international 
standards for RS data formats. Such significant developments 
have significantly broadened the scope and effectiveness of RS 
applications and, in particular, further enhanced the RS 
mapping and monitoring capacities. (Howard et al, 1985; 
Kalensky, 1994; Konecny, 1995; Watkins, 1994). 
2.1 EO Satellites with Imaging Radar Systems 
Clouds prevent recording of good quality images of the earth's 
surface by the optical RS systems used in most EO satellites. 
In some tropical areas, for example in Indonesia and in the 
Amazon region of Brazil or Peru, it can take several years to 
obtain an image with less than ten percent cloud cover by the 
medium-resolution, optical RS system, such as those used by 
Landsat or SPOT satellites. Long delays in data acquisition, 
caused by clouds, have reduced the usefulness of satellite 
optical RS systems in applications where a quick response is 
required. Yet, timely assessment of the extent and impact of 
natural disasters usually requires data on short notice, 
regardless of weather conditions. This limitation of optical RS 
systems has now been overcome by the increasing availability 
of satellite imaging radar systems for civilian applications. 
The recent advent of EO satellites with imaging radar systems, 
such as the Canadian RADARSAT, the European and 
Japanese ERS series of satellites and the Russian Almaz, has 
significantly advanced the production of timely RS data. This 
new generation of EO satellites is using a synthetic aperture 
radar (SAR) for recording image data of the earth's surface 
and its features. Satellite SAR systems emit microwave 
radiation to the ground scene and record the backscattered 
part, which is then used to reconstruct an image of the original 
scene. Since the SAR systems are using their own source of 
microwave radiation, rather than depending upon reflected 
solar radiation, they can record images day-and-night 
Furthermore, due to the properties of microwave radiation, the 
SAR systems produce clear images of ground surface under 
most weather conditions, even through heavy clouds, rain, 
falling snow and fog. For example, the first RADARSAT 
image, recorded over Cape Breton Island, Canada, on 28 
November 1995, was acquired under conditions of darkness, 
rain and strong winds. Yet, the image is clear, without any 
deterioration of its quality. 
RADARSAT 1, launched 4 November 1995, is the first EO 
satellite with the SAR payload designed for global, operational 
applications. In addition to the growing worldwide network of 
ground stations for its SAR data, the RADARSAT has onboard 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996 
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