In: Wagner W„ Székely, B. (eds.): ISPRS TC VII Symposium - 100 Years ISPRS, Vienna, Austria, July 5-7, 2010, IAPRS, Vol. XXXVIII, Part 7B
In: Wagi
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THE MULTI-SENSOR LAND CLASSIFICATION SYSTEM
LCS: AUTOMATIC MULTITEMPORAL LAND USE
CLASSIFICATION SYSTEM FOR MULTI-RESOLUTION DATA
A. Beccati* 3,b , M. Folegani 3 , S. D'Elia c , R. Fabrizi 3 , S. Natali 3 , L. Vittuari d
3 MEEO srl, Research and Development, Via Saragat, 9,1-44122, Ferrara, Italy - (beccati, folegani, natali)@meeo.it
b University Of Ferrara, Department of Mathematics, Via Saragat, 1,1-44122, Ferrara, Italy - alan.beccati@unife.it
c ESA - ESRIN, Ground Segment Department, via Galilei 1,1-00044, Frascati, Rome, Italy
d University of Bologna, DISTART, Viale Risorgimento 2,1-40136, Bologna, Italy
Technical Commission VII Symposium 2010
KEY WORDS: Land Cover, Land Use, Modelling, Web based, Global, Multiresolution, Multi temporal, System
ABSTRACT:
Providing land use/land cover change maps through the use of satellite imagery is very challenging and demanding in terms of
human interaction, mainly because of limited process automation. One main cause is that most of land use/land cover change
applications require multi-temporal acquisitions over the same area, that introduces the need for accurate pre-processing of the
dataset, in both geo-referencing and radiometry. Moreover, single multi-spectral images can be hundred of megabytes in size and
therefore image time series are even more difficult to be handled and processed in real time. The approach here proposed foresees
the use of a robust land cover classification system named SOIL MAPPER® to reduce input data size by assigning a semantic
meaning (in the land cover domain) to each pixel of a single image. Land cover transitions and land use maps can be expressed as
evolutions of land cover classes (features) on temporal domain. This permits to define ‘trajectories’ in the features - time space, that
define specific transition or periodic behaviour. The target system, named Land Classification System, provides fully automatic and
real time land use/land cover change analysis and includes fundamental sub-systems for accurate radiometric calibration, accurate
geo-referencing (with geolocation within the pixel size) and accurate remapping onto an Earth fixed grid. The characteristics of the
selected pre-classification system and Earth fixed grid allow general application across different sensors. Land Classification System
has been prototyped over 15 years of global (A)ATSR data and foresees integration of over 3 years of regional ALOS-AVNIR-2
data.
1. INTRODUCTION
Land use and land cover change (LULCC) topics are going to
become more and more critical subjects for the impact they
have on the global climate. They are in fact linked to climate
and weather in complex ways and are fundamental inputs for
modelling greenhouse gas emissions, carbon balance, natural
ecosystems and human environment evolution. Both human
activity and natural phenomena can affect many of these
processes, that are strictly correlated, influence each other and
have strong impact and consequences on environmental, social
and economic aspects as well as on human health. Land cover
refers to everything that covers the land surface, including
vegetation, bare soil, buildings and infrastructure, inland bodies
of water, and wetlands. Land use refers, instead, to societal
arrangements and activities that affect land cover (Mahoney et
al„ 2003).
Local-to-global scale LULCC studies and application has got
great benefits from the use of remotely-sensed data, mainly due
to the preferred point of view of satellite platforms for the
periodic monitoring of the territory. Besides existing long time
series of satellite data archives, there is an ever increasing
availability of satellite images with global coverage from
different sources and at different resolutions. As a drawback,
single multi-spectral image can be hundred of megabytes in size
and the real time utilization of these datasets for online analysis
is a technological challenge by itself; that, paired with the high
amount of time required for semi-automated image analysis
suggests that fully automated pre-processing systems shall be
used to improve satellite data exploitation and reduce the data
volume at the same time.
In order to improve multitemporal satellite data usability for
time series analysis, accurate image pre-processing operations
shall be performed to make time series datasets homogeneous:
the most important pre-processing steps are accurate
geolocation and accurate radiometric calibration; digital
numbers to radiance or surface reflectance conversion must be
performed for quantitative analyses of multi-temporal images
(Lu et al., 2004). Precise geolocation and image registration are
to be addressed on a per-sensor basis, since each one has its
geometric properties and correction factors.
The proposed generalised approach, named Land Classification
System (LCS), aims at exploiting advanced applications for
single image feature extraction, providing easy-to-use tools for
land use and land cover change detection analysis over time
series of data; such approach, to be readily usable by the
scientific community and also by end users of land cover and
land use maps, is also aimed at providing a computer aided
modelling and land cover evolution analysis tool for definition
of evolution models by domain experts and an high degree of
automation for evolution models application in an effort to ease
and speed-up the analysis of land use and land cover change
phenomena, possibly in conjunction with other tools to find
correlations among different factors influencing life on Earth
like global climate.
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