An apparatus for controlling a plurality of imaging sensor nodes producing 3D structure of a scene is provided. The apparatus receives (500) location data from the sensor nodes, the location data indicating the locations of the moving objects, compares (502) the location data received from different sensor nodes at the same time instants with each other and determines (504) which detections of different sensor nodes relate to same moving objects. The apparatus further maps (600) the location data received from different sensor nodes to a common coordinate system and determines (602) the relationships of the fields of view of the sensor nodes with each other and the location data mapped to the common coordinate system.