Research project OR/11/004 (Research action OR)
Objectives
Up-to-date knowledge of land cover is an important tool for the various planning authorities with responsibilities for the management of territory. The geospatial objects are changing over time and the land cover information (vector geospatial database) has to be up-date periodically.
The vector geospatial databases at a local scale in Belgium were carried out by digital cartographic production process based on aerial photographs, and the update of these databases is now at the agenda. Until now, interpretation of aerial photographs is a standard
tool for monitoring land cover change where fine spatial resolutions are required and this task is expensive and time-consuming. Though, from a spaceborne perspective, the VHR satellite data are, since 1999, capable to meet the mapping and monitoring needs of municipal and
regional planning agencies. Indeed, these data from the sensors Ikonos, QuickBird, OrbView-3, and in near future, the Pléiades-HR French sensors, have spatial resolution lower than 5 m in multispectral mode and lower than 1 m in panchromatic mode.
The objective of the post-doctoral project is to study the potential of the Pleiades-HR data to detect changes for updates of vector database through multi-level region-based classification.
It should lead to the identification of the objects that can be update in the vector databases with the Pleiades-HR data and to know if these changes will be simply located and/or delineated and/or identified.
The project will be carried out with three privileged end-users for whom the needs will be assess at the beginning of the project. The three end-users that play a key role in the production, the use and the distribution of vector geographical database are Agriculture Directorate-General
with its crop field database, National Geographic Institute with its 1/10000 topographic maps and Walloon Ministry of Transport and Equipment with its “Projet Informatique de Cartographie Continue” (PICC). These databases have different objectives and different scales, but they
are made up of the same kind of objects represented among other by polygon. That could allow to find a common method to detect the changes and/or the errors in the different vector databases with Pleiades-HR data.
Another objective of the project is the integration of 3D information coming from the partners of the network (RMA/SIC and CSL/ULG) in the change detection processes and the study of the 3D contribution. The radar component (Cosmo-Skymed) of the Optical Radar Federated
Earth Observation (ORFEO) program, through interferometry will allow photogrammetric processing, creation of digital surface model in order to orthorectify the satellite data and that can be useful additional information in the classification process.
Methodology
- Vector database manager (end-user) requirements
- Selection of study areas and data collection
-Geocoding and ortho-rectification of VHR images and co-registration with the vector database and other ancillary data
- Class definition and training
- Generalisation and pre-processing on the vector geospatial database
- Development of the change detection methods integrating region-based classification
- Assessment of the change detection methods integrating region-based classification
- Technical and economical assessment
Study area
Arlon and vicinity
Data
VHR
