International spheroid 1924
1951 UNIFIED EUROPEAN GEODETIC DATUM.
Belgian LAMBERT projection
Levelling datum : Zero D at Oostende + 2.32 m (REUN)
Gravity datum : Uccle 1976.
The anomalies are calculated using a uniform Bouguer reduction density of 2.67 gr/cm3 the grid was obtained by Krigging, cell size : 5 km, search radius : 30 km. The French data are copyrighted by BRGM (France).