Jean-Paul Donnay

Use of Remote Sensing Information in Planning

Remote sensing includes photo-interpretation and photogrammetry. Both these techniques have contributed, and still contribute today, to many planning processes since they constitute major ways to collect geographical or geocoded data It has become relatively easy to scan aerial photographs and to store the results (computer assisted photo-interpretation) in digital form in geographical databases. The key question is whether satellite remote sensing is useful for planning purposes. Can we consider satellite imagery as a surrogate for standard data sources in planning? Is satellite remote sensing able to cast new insights into certain planning practices? If so, can the digital form of the satellite images make its integration easier in geographical databases and information systems? This chapter addresses those questions, twenty five years after the launch of ERTS-1 (Landsat-1), ten years after the advent of the ‘second generation’sensors (SPOT HRV) and at the beginning of a new epoch which will be characterised by an immense and diverse supply of satellite images.

MECOSIG adapted to the design of distributed GIS

For more than ten years MECOSIG has been used as a method for GIS design and implementation in various national and international projects achieved in our laboratory. During a decade, the method has been progressively improved and extended without modification of its basic principles. However the emergence of distributed GIS, implying several organizations capable to play various roles, requires the reappraisal of the methodology. New concerns are identified and a collection of new tools must be deployed. Taking the most of various recent researches completed for public authorities in Belgium, this paper presents some significant adaptations of the original MECOSIG method in order to cope with a distributed GIS environment.

Reconstitution of the Journeys to Crime and Location of Their Origin in the Context of a Crime Series. A Raster Solution for a Real Case Study

In the region of Charleroi (Belgium), a series of criminal acts were committed by the same group, using the same vehicle. The events were located in space and time. The car used during these criminal activities was stolen (first event) and was later retrieved (last event) after a period of 4 days of offences. Police recorded a crucial clue: the total mileage covered by the vehicle between the first and the last event was estimated with an admissible approximation. Thanks to this information, we were able to choose the most probable journey-to-crime among several scenarios. These depended on the combination of cost surfaces built with distance propagation algorithms starting from each criminal event in raster mode. The distance propagations were limited to the road network and the combinations of the cost surfaces had to respect the chronology of the facts. The most plausible scenario suggested that the criminals hided the car into a withdrawal site between their activities. In order to improve the precision of the location of this withdrawal site, we used a multi-criteria analysis taking account of the journey of the vehicle and other environment variables. At the end of these treatments, the small stretch of road that we isolated actually included the withdrawal site, as confirmed by the police later.

Localisation des caméras ANPR sur le réseau routier pour le profilage géographique

Malgre un recours croissant a la technologie des cameras ANPR, en particulier dans les investigations criminelles, la litterature et l’experience des forces de police avec lesquelles nous avons travaille, semblent montrer qu’il n’existe pas de methode systematique afin de localiser le plus adequatement possible ces installations couteuses. Partant d’un ensemble de delits localises, relevant de quatre categories de vols perpetres sur une annee au sein de la province de Liege (Belgique), nous proposons une methodologie exploitant, dans une analyse multicritere, la densite de delits, la densite de voirie et la distance entre les sites des cameras. L’approche multicritere permet d’ajuster la ponderation des facteurs selon les types de delits. En outre, la methodologie est iterative, dans la mesure ou les sites des cameras sont localises par phases successives. Un critere de validation des resultats est fourni sous la forme d’un taux de couverture du territoire considere, qui est fonction du nombre de sites de cameras retenus et du temps de parcours depuis chacun de ces sites. De plus, les consequences des tentatives d’evitement des sites installes en matiere de profilage geographique sont rapidement evoquees.

Impact de l’anisotropie du milieu dans les études de profilage géographique

Cet article a pour objectif d’evaluer le biais introduit par l’usage de la distance euclidienne dans le cadre d’analyses de profilage geographique. Elle procede par une comparaison des distances routieres et euclidiennes calculees sur pres de 1 000 couples d’origines-destinations (sites de crimes – point d’ancrage du criminel) issus de la base de donnees de la police federale belge. Les comparaisons sont differenciees selon la densite du reseau de voirie (milieux rural et urbanise) et les parametres statistiques des distributions resultantes sont exploites dans l’application du modele de decroissance avec la distance, principal outil de profilage geographique.