Indoor video surveillance networks as typically used in retail-networks need to be consistently calibrated with respect to a global coordinate system to provide the spatial context required for automatic recognition. This can be problematic if the .eld of view of the cameras are disjoint. This paper presents a strategy to calibrate disjoint views into one coordinate system. The system is based on a device which can calculate its current position and orientation with respect to the global coordinate frame while it traverses the entire site without requiring direct line of sight between all sets of points. The paper explains why more traditional approaches have disadvantages and presents experimental results using the new method.