Procedures for global Calibration and Validation (CAL/VAL) of satellite remote sensors and measurements have been developed based on Geographic Information System (GIS) technology. CAL/VAL of EOS sensors and measurements are demonstrated, integrating simultaneous and collocated "truth" data from ground based and airborne in situ and remote assets. GIS provides broad capabilities "out of the box" for data acquisition, management, imaging and processing in arbitrary multiple dimensions, including spatial/relational methods in time and space. GIS can also incorporate external user functions and programs with a user-configurable interface, and can be quickly adapted to changes in sensor operating characteristics and environment. Examples are shown for the August-September 2000 SAFARI Field Experiment over Southern Africa.