Abstract: A rate measuring instrument uses acoustic energy transmitted through a crystalline media (41) to sense rate. Acoustic energy travels along a path (1-31) within the crystalline media and impinges upon an output transducer (45) at an established point after being reflected a number of times from facets (47) of the crystalline media (41). Rate information is detected as a shift in the point of impingement of the greatest amount of acoustic energy upon the output transducer (45).

Abstract: An optical filter device is disclosed made up of a specially designed bandpass filter and a circularly polarizing filter and is typically used in front of the faceplate of a cathode ray tube in a high intensity ambient light environment, such as with navigation displays in some aircraft cockpits, to reduce the high intensity ambient light striking the phosphor of the cathode ray tube and thus effect a reduction in the level of the scattered light that causes a washout of the display thereon, thereby permitting observation of the display on the tube.

Abstract: A front for test patterns is made programmable by programming individual "characters" to be displayed on a video display. The individual characters are assigned memory locations and can be adjusted in height and width, as well as in color and intensity. Complex characters are formed by programming additional features onto a character memory space assigned to each character. The system provides a greater ratio of pattern generating capability-to-required hardware, while providing most features of a fixed character generator. The system's programmability is particularly adapted to use with a test system which has capabilities of incrementally varying scan rate and raster patterns, as well as a capability of random stroke and fixed mode stimuli generation.