Abstract: A digital tracker which provides a continuous display of the area tracked mprising a delay line coupled in circuit with a comparator, a video digitizer and a sensor. The digital tracker further comprises circuit means connected between the delay line and the sensor for deriving an error correction signal in response to any mismatch between the present, delayed video scene and the reference scene, stored in the delay line. A staircase raster generator which can be positively synchronized with the delay line through the use of a common master clock is used as the sensor and the delay line is a shift register which enables any desired bit of the stored signal to be available for use at any time.