Abstract: Disclosed is an apparatus and method for determining the presence and position of a moving object within a static field. Basically, the invention utilizes a photocathode in combination with a storage mesh whereby a distributive charge may be stored upon the mesh indicative of light levels within the field. Positive and negative write operations are exercised at different points in time and are superimposed upon the storage mesh. The mesh is then read by means of deflection coils in combination with an aperture plate so as to sequentially scan the storage mesh and emit output signals correlated with the charges upon the mesh after positive and negative write cycles have been exercised. The invention incorporates the fundamental structures of an optical image correlator tube and an image dissector tube.