Correction of Buildings, Basements and Bridge Influences in an Urban Microgravimetry Survey

A001 CORRECTION OF BUILDINGS BASEMENTS AND BRIDGE INFLUENCES IN AN URBAN MICROGRAVIMETRY SURVEY 1 Summary A microgravity survey was carried out in summer 2002 and 2003 for modelling the molassic bedrock in Lausanne a high-urbanized city in Switzerland. The project of a new underground determined the availability of continuously updated mechanical loggings data that permitted us to check our models and to find out a routine procedure. We could evaluate influence of basements and large buildings. Firstly we had to ameliorate the digital elevation model (DEM) to have precise near topographical corrections and exact interfaces between basements and topography. Roads