A Sensing System for Dash-Dot

A system of dynamic armor for tanks (Dash-Dot) is under investigation. A successful system will sense the presence of an anti-tank round, compute it trajectory, and defeat it by automatically firing defending charges that will destroy the attacking rounds before impact. A sensing system of three optical screens, employing filtered IR sources and photo-conductive detectors (PbS cells) has been devised. Preliminary evaluations of the physical and geometrical detection parameters are discussed. In tests of an experimental screen system, an accuracy of about 3% has been achieved in determining the unknown altitude and velocity of 75 mm shells at velocities up to 2500 fps. Preliminary calculations on the complete geometry of the system are presented as an appendix.