The new tools for a global survey of potential sites for the future giant telescopes

The siting of future giant telescopes poses a challenge to the astronomical community. Some of the top level existing observatories are already too crowded; others do not meet the specifications on particular environmental parameters such as wind or seismicity. On the other hand it has been proven that continental sites can be as good as islands, opening the way for many candidates not yet properly studied. To operate a pre-selection, it is proposed to implement a dedicated geographical information system (GIS) handling the wealth of available remote sensing data worldwide. When focusing onto particular summits, the GIS should then be complemented by mesoscale modeling of the local flow. Some examples are given to support this strategy.