SISelune: new base maps
The cartographic portal of SISelune, the information system of the Sélune scientific program, has new base maps. These new backgrounds maps benefit from the IGN geoservices and their open data. You will be able to see the Sélune in a different way, to find your way around and finally to print your own map.
This news is an opportunity to make a complete review of the map backgrounds available in SISelune.
How to change the base map?
In the cartographic portal, click on the thumbnail at the bottom right to change the base map
The eleven available backgrounds (at the time of this writing) line up vertically.
Hover over one of the thumbnails to get a quick description of the base map.
Orthoimages
Orthoimages are aerial or satellite images of the earth’s surface. These images are corrected, both in terms of geometry (rectification) and ‘colors’ (radiometric equalization). They are shown as localized (georeferenced) tiles covering an area of the Earth. Several major orthoimages exist:
BD Ortho (IGN)
The BD ORTHO® is a collection of digital mosaics of aerial color orthoimages. It covers the French territory, with an update rate of 3 or 4 years (about thirty new departments produced each year). BD ORTHO® is produced by default with a 20 cm resolution, both in natural and infrared color.
BD Ortho – natural color
The classic “natural color” product is available in its current version (left) and in several earlier editions. You can thus “go back in time” and see the changes in the landscape.
BD Ortho – historical
This collection of digital mosaics of old aerial orthoimages, in grayscale, allows to see the Sélune from the sky, in a period between 1945 and 1965
BD Ortho – False color (IRC)
This mosaic, called “Near Infrared False Color” contains 3 channels with: near infrared, red and green. The presence of near infrared highlights the active vegetation.
Esri World Imagery
ESRI company provides ‘World Imagery’, another collection of recent orthoimages (typically less than 3 to 5 years old), with a one meter resolution or better in many parts of the world.
Note that the background typically displays satellite images at coarse scales and aerial images for finer scales. The IGN uses the same approach for its current BD Ortho (but not the older editions)
Map plans
OpenStreetMap (OSM)
OSM is a world map, built by a community of volunteer cartographers and free to use (under free license).
OpenStreetMap is also available as a light base map. This version, called “positron” and produced by CartoDB, is suitable for printing your maps on paper.
Plan (IGN)
This map plan has been designed for screen use and gives a precise and readable display, whatever the scale (up to 1:1000).
Military staff map
This 1:80000 map from the 19th century (1820-1866) is the most recent one, before the dams were built.
Need more base maps in SISelune?
We have selected 11 base maps to meet the maximum needs. Other maps exist. If you think an important background is missing, feel free to contact the SISelune architect.
