Abstract: 3. Automatic target following apparatus comprisingA. sensing means for deriving a video signal representing a target,B. means for storing signal elements from a frame of said video signal,C. means for comparing signal elements from a subsequent frame of said video signal with the stored signal elements with different relative phase shifts to detect deviation from a desired point of view of the target,D. said comparing means including means for deriving a plurality of correlation signals dependent on the correlations of the signal elements from said subsequent frame and said stored signal elements with different relative phase shifts,E. means for deriving a guidance signal for the apparatus responsive to the largest of said correlation signals,F. means for detecting a decline in the correlation of signal elements from said subsequent frame with said stored signal elements, andG.