Abstract: A fragment-sealing bullet trap for rifle muzzle launched projectiles having a soft aluminum plug for decelerating and absorbing the softer components of rifle bullets, followed by a shock absorbing piston to mitigate the peak acceleration of the projectile due to bullet impact, in turn followed by a hardened steel anvil to safely capture any steel bullet components. Attached to the aft portion of the plug is an aluminum cap, containing a rubber gasket, which expands during bullet penetration, but rebounds due to its resiliency, tightly sealing off the bullet trap against the escape of bullet and plug fragments. The cap is designed to prevent the gasket from blowing out as a result of high bullet trap pressurization.

Abstract: A muzzle launched grapnel hook projectile having a body with an internal cavity which is sized to fit over the muzzle end of a rifle or spigot. A bullet trap within the internal cavity permits launching of the projectile one time with a live bullet cartridge as the propulsion force. The projectile can then be launched multiple times with a blank propellant cartridge. The front of the projectile mounts several torsion springs which serve as tines to grab trip wires and detonate trip wire mines as the projectile is being dragged back to the launch point. The torsion spring design and mounting scheme permits the tine to bend and release from non-trip wire obstacles along the retrieval path. Attached to the base of the projectile at a flange is a bridle consisting of multiple leader lines. Pulling on the bridle causes the leader lines to come together to form a cone-like surface which allows the base of the projectile to slide easily over obstacles.

Abstract: In a digital moving target indicator (MTI) employing digital filters for rejecting low frequency clutter signals having magnitudes which are 20 to 60 db greater than the moving target return signal, the dynamic range and resolution accuracy requirement of an analog-to-digital (A/D) converter, used to convert the return radar analog video signal to a plurality of digital signal equivalents for presentation to the digital filters, is reduced from that normally required by prefiltering the return video signal through a prefilter network.