 A DRFM may modify the signal prior to retransmitting which can alter the signature of the false target; adjusting its apparent radar cross section, range, velocity, and angle.DRFMs present a significant obstacle for radar sensors.The earliest reference to a digital means of storage of RF pulse signals is an article in the Jan/Feb 1975 issue of Electronic Warfare, a publication of the Association of Old Crows, written by Sheldon C. Spector, entitled "A Coherent Microwave Memory Using Digital Storage