Abstract: An athletic implement, having a self-contained, built-in system for measuring impact between the implement and a struck object and for displaying the distance traveled by the struck object is disclosed. In the disclosed preferred embodiment, the athletic implement comprises a golf club having an acceleration sensor mounted in the club head for detecting the deceleration shock pulse generated upon striking a golf ball with the club head. The sensor transmits an analog electrical signal proportional to the peak amplitude of the shock pulse to battery-powered electronic circuits mounted in the club handle. The electronic circuits convert the analog signal to digital signals proportional to range or distance traveled by the ball and transmits the same to a decoder/driver which drives a digital display such as a LCD or LED display mounted in the end of the club handle.

Abstract: A hydrophone array system comprising a plurality of hydrophones fastened to a cable is deployed beneath the sea in a substantially horizontal straight line. A small powered thruster fastened to one end of the cable urges it in a first direction and this urging is resisted by a member, such as a drogue or an anchored subsurface float, fastened to the other end of the cable. Individual signals from each of the hydrophones are conducted to the surface where they are processed and transmitted by a radio link to a nearby aircraft or surface vessel. Beam forming and analysis is performed aboard the aircraft or surface vessel.