ENVIRONMENTAL MONITORING IN THE HIGH ARCTIC
USING DIFFERENT TYPES OF HIGH-RESOLUTION SATELLITE IMAGERY
Gerhard Brandstätter
Professor, Graz University of Technology, Austria
Aleksey Sharov
Associate-Professor, Moscow State University of Geodesy and Cartography, Russia
Comission VII, Working Group 3
KEY WORDS: Topographic Monitoring, Change Detection, Image Interpretation, Multisensor Data Fusion, Radar Interferometry
ABSTRACT
Several approaches to spaceborne image processing based on multisensor data fusion including
- image differencing technique applied to multitemporal spaceborne imagery, aerial photographs and available maps;
- . combined photogrammetric processing of KATE-200 stereoscopic photographs and precision ERS-1-SAR images;
- inerferometric analysis of complex satellite SAR images and joint interpretation of INSAR products and stereoscopic models;
have been investigated and practically applied for operational monitoring of topographic-glaciological changes in the Franz Josef Land
archipelago, Russian High Arctic. A new concept of satellite topographic monitoring in the High Arctic is offered and argued.
1. INTRODUCTION
The High Arctic, i.e. the northernmost circumpolar
physiographic region of the globe poleward of latitude 75? N,
comprises a great number of large and small islands surrounding
the interior deep-sea Arctic Basin with drifting sea ice.
According to UN standards nearly 500 of these deserted islands
are regarded as part of Europe. Thus, the total area of the
European Arctic deserts occupying the archipelagoes of
Spitsbergen, Franz Josef Land and Novaya Zemlya can be
approximately estimated at 125.5 thousand square kilometers,
which accounts for about 1.296 of the land surface of the "old
world". Its extreme geographic location, unusual natural
conditions and minimal human impact, the attractive beauty of
its wilderness and a number of "white spots" in Arctic
geosciences excite great scientific and public interest in this
region. Apart from its economic and political significance the
European Arctic is internationally acknowledged as a uniquely
fruitful area for conducting comprehensive environmental
research.
In spite of traditional public opinion on such areas as being
"natural refrigerators" experiencing one of the slowest rates of
changes worldwide, the majority of scientists suppose that the
high Arctic environment is subject to rapid changes due to the
impact of ice, wind and water. In addition, environmental
changes are brought about by active tectonic processes, which
are still continuing in this region and heavily influence the
evolution of Arctic archipelagoes (Matishov 1993). Moreover,
and in contrast to Antarctica, the High Arctic is a region where
the consequences of global environmental changes, notably
climatic changes, are likely to be particularly severe. Therefore,
it is reasonable to suppose that changes in size and physical
characteristics of the Arctic ice caps are an important mechanism
controlling global climatic change (Diament et al. 1993). Since
movement is an inherent quality of any glacier, time series of
systematic observations and analyses of interrelations between
them, i.e. long-term monitoring, are needed to determine if these
changes are of local origin or caused by variations of global
climate patterns. The reliable models describing the dynamics of
Arctic landforms and indicating the origin of environmental
changes would be of fundamental significance for both basic
geosciences and further multidisciplinary explorations in the
High Arctic. Modes and trends of spatial changes as well as
features of glacial evolution also need to be known for planning
and conducting long-term economic projects, prospecting and
Intemational Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 7, Budapest, 1998
rational utilization of natural resources, environmental protection
initiatives, appropriate administration and sustainable
development of Arctic regions.
Techniques making use of artificial polar-orbiting satellites and
digital information technologies are believed to be the most
effective tools for discovering environmental changes in remote
and inaccessible Arctic regions (Brandstitter 1997). It should be
stressed, however, that the use of modem developments in
satellite remote sensing and GIS technologies for environmental
monitoring in the extreme conditions of the High Arctic is still
largely unexplored and, thus, is of special practical importance
and scientific interest.
The general idea of our work was to evaluate and utilize the full
potential of satellite remote sensing for monitoring
environmental changes in the European High Arctic by means of
multisensor and multitemporal remote sensing data fusion. Main
emphasis has been put on topographic aspects of natural
exploration and monitoring in the High Arctic, and major
attention is paid to the following objectives:
I. Argumentation of the concept of satellite topographic
monitoring in the High Arctic.
2. Development of an efficient methodology for reliable
topographic and topological modeling of high Arctic terrain
on the basis of multisensor and multitemporal remote
sensing data.
3. Designing principles and algorithms for joint topographic-
glaciological interpretation of spaceborne optical and radar
images.
4. Detection and classification of present topographic changes
in FJL at regional and local level.
A chapter explaining the idea of satellite topographic monitoring
in the High Arctic precedes the description of our theoretical and
practical investigations.
2. GENERAL CONCEPTS OF SATELLITE
MONITORING IN THE HIGH ARCTIC
2.1 Background
The dynamic environment and high rates of natural changes, the
remoteness from economically developed regions and harsh
environment impeding both aerial surveying and extensive field
work are the principal causes for applying satellite monitoring in
high Arctic areas, where natural features are predominant,
201
