Abstract: A thermophotovoltaic system includes structure defining a diffusion flame burner having separate but adjacent fuel and oxidant inlets, and structure defining a combustion chamber in which an emitter structure is disposed for exposure to combustion products of the burner. The combustion products heat the emitter structure and cause the emission of spectrally distributed radiation. Disposed in optically coupled relation to the emitter structure are one or more photocells for converting energy radiated by the emitter structure to electrical energy, a close match between the spectrum of the photon energy radiated from the emitter structure and the electron production threshold of the photocell array resulting in enhanced efficiency. One portion of the combustion product stream is flowed from the combustion chamber through a recuperator to heat the incoming oxidant, and another portion of the combustion product stream is flowed into the combustion chamber.

Abstract: A video data acquisition system takes at least two snapshot views of selected points on a golf ball in the immediate post-launch time period. Analog video data are converted to digital data for analysis in an external system.A trigger generator, of a type well known in the art, senses the existence of a certain set of conditions associated with the launch of the golf ball and thereupon generates a set of precisely timed impulses which trigger the following sequence of events:(a) prepare TV camera to receive data(b) trigger first flash(c) trigger second flash(d) read out data from TV camera.

Abstract: A measurement system obtains and stores digital data on the positions of golf club and significant human body parts during a golf club swing. An interactive display allows later display of the measured performance for use in instruction or review. A coordinate transformer allows the viewing of a displayed simulated golfer from any aspect and at variable speeds and stop action. A generator such as an alphanumeric or graphic generator displays suggested display options, graphics, informative labels, and alphanumeric tabular data. Permanent copies of any displayed picture can be made for later home study.

Abstract: Electro-optical sensors measure the location of a plurality of spots on the surface of a golf club head or a golf ball at a minimum of two precisely spaced points in time. The two time points for the club head are just prior to impact with the golf ball. The two time points for the golf ball are just after impact by the club head. From the apparent displacements of the plurality of spots between measurements, the apparatus determines in substantially real time the velocity of the club head or ball and the spin about orthogonal axes.

Abstract: A photographic projection screen formed of separate parallel filaments having a center-to-center spacing equal to their diameters allows a projectile to be driven through it with minimal disturbance to image projected upon it.