Context and objectivesUp to now the use or satellite images for change detection in urban areas is not popular due to the resolution of the sensor. This might be changed with the new available sensors with a very high resolution.
Even for GIS projects, the Municipality of Ghent has never used a satellite image before. As higher resolution images become widespread (e.g. Space Image IKONOS-1, resolution 1m), these images could also be used for "local level" studies.
Further development of the website of Ghent is a possible way for helping people to come to a better insight into remote sensing documents, specifically those images concerning people's own environment (the town of Ghent and surroundings). For that purpose yet available archive and more recent images will be used. The examples that will be developed are illustrating the multitemporal and multiscale approach.
There are 5 themes selected:
1. Ghent and the world: Landsite MSS image of Ghent and its 6 sister towns projected on a world overview, with geographical description of each of them.
2. "Change" detection: Comparison of imagery of the eighties and the nineties with specific attention to urbanisation and green belt supply.
3. Multiscale approach: to show people how Ghent is "looking" on the images of different sensors with different resolutions, using an image sequence starting from rough resolution images (NOAA-AVHRR) through medium resolution images (archive images of Resurs-01 and/or Landsat MSS) up to fine resolution images (SPOTXS and/or SPOT-P).
4. Following theme 3 theme 4 concerns the utility of the Russian KVR-1000 sensor images and/or the Space Image IKONOS-1 images for studies of small areas as citizens' own environment, zooming in on these high resolution images on the Internet.
5. Comparison of the high resolution images with available aerial photographs selecting 2 areas in Ghent, e.g. the dock area and the town centre.
Each of the presented images and approaches will be discussed in a brief text. In such a way the Internet user can have a better understanding about the technology and methodology of the remote sensing documents.
Expected scientific results
Ghent is presented by 6 different kinds of satellite sensors (Noaa AVHRR, Landsat TM and MSS, Landsat 7 ETM+, SPOT, Ikonos 2) and two scales of aerial photographs (45cm resolution and 10cm resolution). Most important is the zoom on Ghent from low to high resolution images ending with aerial photographs with 10cm resolution. In these way the difference between low and high resolution images is explained. While navigating pop-ups will give the information about the location.