3.2. Input data

The OnoM@p system uses two types of data in order to build analysis and geographical indicators.

OpenStreetMap

The OSM API (http://wiki.openstreetmap.org/wiki/API_v0.6) is be used to extract on demand OSM data in a XML format. Thanks to the H2GIS functions (http://www.h2gis.org/docs/dev/ST_OSMDownloader/ and http://www.h2gis.org/docs/dev/OSMRead/) that permits to download and transform the XML file into a set of tables stored into the OnoM@p spatial database. This tables will be processed in SQL to create a layer of buildings and a layer of roads. The road and building layers will be exploited to evaluate the quality of the noise measure (in or out a building) and to compute noise indicators. What is the maximum noise level in or near a road ?.

IRIS CONTOURS

The IRIS contours is a set of French statistical geographic zones (polygons). All municipalities with more than 5,000 people are cut into quarters of approximately 2,000 inhabitants. Each zones are accompanied by statistical indicators related to the French census. A unique identifier is used to join the census statistics with their geographical representation.

Census statistics

The census data covers 70% of the French population (http://www.insee.fr/en/methodes/default.asp?page=sources/ope-rp.htm). Aggregated to the IRIS areas the population statistics will be used to compute population exposure indicator in accordance with European Directive 2002/49/EC.