Abstract: A transmitter directs a narrow RF ultrasonic beam through a body cavity to a receiver on the other side of the cavity. The beam is steered to be intercepted by audio signal sources in the body cavity, such as a fetal heart or multiple fetal hearts, which modulate the ultrasonic beam. The received parametric beam is demodulated and filtered to provide a relatively noise free audio reproduction of an audio signal source. In one embodiment, two transmitters are steered independently to direct respective beams to respective receivers to produce two signals and, thus, a binaural audio reproduction of an audio signal source. The audio reproduction is at a maximum when the two beams intersect at the audio signal source.

Abstract: Many sensor information processing applications currently use monochrome B-scan presentations to exhibit processing results from radar, sonar, spectral estimation, seismic profiling, radio astronomy, bio-engineering, and infrared imaging. The use of color for such raster display presentations have been limited to the coding of amplitude values for a fixed set of hue/luminance colors to convey recognition by the human operator. Hue and luminance are used here independently to convey two orthogonal pieces of low signal-to-noise sensor information simultaneously to the operator for quick and accurate recognition. The net result is an added degree of freedom available on a single display surface, which not only improves operator recognition and reaction time for critical events, but precludes the necessity of a second display presentation for the alternate information and subsequent correlation of two data sets by visual comparison.

Abstract: Apparatus and method for sonar or radar target tracking. Digital apparatus nd techniques are employed. A variable delay is used for beam steering.