A switch modulated low duty cycle low energy mass limited radio frequency beacon system for locating spent, un-exploded or experimental munitions projectiles in a large open-air test range or within a dirt backstop. The disclosed locator beacon is mounted on a rear portion of a projectile before launch...http://www.google.fr/patents/US6456240?utm_source=gb-gplus-shareBrevet US6456240 - High-G, low energy beacon system
