MAPPING FROM SPACE AT IGN IGN (French National Geographical Institute) was involved in remote sensing from the very beginning of this discipline. It acquired its first image processing system in 1977 and has developped algorithms and software ever since. IGN space related activities were initially focused on the thematic and geometric processing of the LANDSAT images, but were redirected towards cartographic applications upon the launch of the first SPOT satellite in 1986. IGN has, ever since, made use of SPOT imagery in particular, for its suitability to cartography with its high resolution (10 or 20 meters) and its stereoscopic capability. IGN ESPACE can process and geometrically correct images from a wide variety of earth observation sensors, among them SPOT, LANDSAT and ERS. IGN ESPACE was set up in Toulouse (France) in 1986 to meet mapping from space technical production requirement on an industrial scale. IGN ESPACE experienced rapid and continuous growth and developped a wide range of products. a) The spacemap is the product which has had the biggest success so far. It is composed of an orthoimage underlay (geocoded through space triangulation techniques) onto which additional information such as toponyms, contours, cartographic and geographic coordinates and communication networks is overlaid. The spacemap is ideally suited for meeting the demand of urgent mapping or projects. It can be produced very quickly and cheaply to cover sometimes inaccessible areas. It is particularly adapted to large uninhabited areas and regions with sparse existing cartographic information. Consequently, whether it is to monitor the periodic shifts of the Bangladesh rivers or to provide the Department of Defense with cartographic covers of isolated areas, spacemaps are a natural choice. As with conventional maps, they can be used to locate and position objects on the Earth surface. They do not, however, have any key, and conventional map symbols are replaced with image pixels. Spacemaps are not a product for the general public, but rather for professionals used to interpret the sometimes strange colors and shapes of our globe as seen and recorded by satellites. IGN ESPACE is one of the leading specialists in the industrial production of spacemaps. Spacemaps can be accompanied by vector data (roads, hydrography, railroads, habitat etc) delivered in digital form and used as input in Geographic Information Systems (GISs). b) Digital Elevation Models (DEMs) can be obtained trough SPOT imagery. As a result of its stereoscopic capability (the ability to observe an object from two different angles), SPOT imagery can be used to map land relief. This relief automaticaly computed from SPOT digital data can be stored in a computer in DEM format. DEM applications are many : automatic guidance of aircraft, optimum location of fire watchtowers in mountain areas, locating the limits of a future barrier lake or geocoding a satellite image. c) Using SPOT,LANDSAT or ERS imagery, IGN ESPACE makes 'map/image combinations', 'field documents' and 'multidate image series'. - 'Map/image combinations' are 1/10 000 scale products obtained by overlaying a scanned topographic map on the base image. For example, the products were used by the farmers in the Oise departement for marking their declarations of plots left fallow as part of the PAC (Common Agricultural Policy). - 'Field documents' are used to draw up agricultural statistics: these are image extracts used by agricultural investigators to record their land observations, particularly the type of crop. They are drawn up on sites selected on the basis of these statistics. Land observation are associated with the analysis of space images to produce agricultural statistics. This process was implemented for the EEC 'MARS' project (EEC agricultural statistics). - 'Multidate image series' are sets of images of a given site recorded on different dates. They are used for development studies, and for observing environmental changes such as urban growth or deforestation. d) IGN uses SPOT images to map ground cover in France. SPOT imagery is prepared by IGN ESPACE and interpreted in the IGN workshops at Saint Mande. The ground cover is then stored in the IGN cartographic database, covering the whole of France. e) IGN ESPACE markets geometrically corrected satellite image products. IGN ESPACE has developped a SPOT, LANDSAT and ERS geometric modeling software, which is among the best in the world. Its space imagery triangulation software is also used to correct blocks of satellite images using a limited number of ground control points. f) In association with IGN staff in Paris, IGN ESPACE carries out continuous research in the space mapping field, constantly improving its skills in space sensor geometry and digital image interpretation methods. IGN ESPACE know-how is also put to advantage by offering its expertise and training services to french and foreign customers. As well as taking part in national programmes defining future Earth observation satellites, IGN ESPACE is also involved in a large number of national and international associations. At the present time, the head of IGN ESPACE is President of the ICA (International Cartographic Association) 'satellite cartography' commission, and President of the HRO (High Optical Resolution) group of experts acting in an advisory capacity to CNES for long-term satellite programms. Marketing IGN space maps : Abroad : IGN FRANCE INTERNATIONAL is an IGN subsidiary in charge of prospecting the market and following up all projects abroad. The local agency for IGN FRANCE INTERNATIONAL, located in the Parc Technologique du Canal, deals with any projects concerning mapping from space or involving a Toulouse operator. In France : The IGN commercial agency looks after the advertising and distribution of every IGN product: maps, aerial photography, digital products from the IGN databases, customized jobs and services. The aim of grouping these three services in one building is to ensure coherent marketing: IGN ESPACE products are marketed by IGN FRANCE INTERNATIONAL for foreign territories and by the IGN sales departement for France and military customers. As of July 1994 IGN ESPACE has 31 employees including 10 engineers, 2 surveyors, 17 operators or draughtsmen and 2 secretaries, and produces 1300 spacemaps per year with 3 Vax computers, 3 tape handlers, 6 I2S image processing stations, 2 SUN workstations and 5 Macintosh stations (for cartographic work). IGN ESPACE handles 3000 km of magnetic tape per year, operates over 5 continents and makes full use of its 36 Gigabytes of computer memory. IGN ESPACE/IGN France International/IGN Agence Commerciale Parc Technologique du Canal 24 rue Hermes 31527 Ramonville-Sainte-Agne Tel: 33-62 19 18 18 Fax 33-61 75 03 17 End_Group
FR/IGNE
FRANCE