Electronic wavefront subtraction in longwave holography

A new electronic wavefront subtraction method, particularly suited for use in scanned longwave (microwave and acoustic) holography, is described. In addition to its relative simplicity, the method has the advantage of not requiring the stringent exposure and registration controls necessary in conventional fully optical holographic wave-front subtraction that rely on photographic contrast reversal and contact printing. In addition, the method provides a useful and rapid means of selecting optimal operating conditions.