Abstract: A signal transfer device measurement system and method of the present invention measures the signal transfer characteristics of a device under test (DUT) having an analog input port and either an analog output port or a digital output port. The measurement system and method comprise a stimulus waveform generator that produces a stimulus waveform. The stimulus waveform comprises a time sequence of pairs of narrow bandwidth, modulated signals. The stimulus waveform is applied to the input port of the DUT thereby producing an output response signal at the output port of the DUT. For a DUT with an analog output port, the measurement system and method further comprise an analog-to-digital converter (ADC) for digitizing the output response signal and producing digital data and a signal processor for processing the digital data thereby producing measured results.

Abstract: A horned interferometer antenna apparatus has parallel plates spaced apart and rigidly connected together by a separator. In the space between the parallel plates is a plurality of antenna elements. The parallel plates each have a free edge which diverge from the other free edge defining an aperture for receiving electromagnetic waves. The horned interferometer antenna apparatus has enhanced directivity and is used for passive radio direction finding. An interferometer system comprises a horned interferometer antenna apparatus, a multi channel receiver and a phase comparator. The interferometer system measures the angle of arrival of an incident electromagnetic wave or signal based on the phase difference between the signal as received by the antenna elements of the horned interferometer antenna apparatus.

Abstract: An optical monitoring system maps high aspect ratio regions of space using an imaging or viewing device that has a field of view with a low aspect ratio and a plurality of mirrors positioned and arranged relative to the imaging device and the region of space such that the plurality of mirrors directs the image of the region of space to the imaging device in a plurality of segments. Each of the segments is smaller than the field of view of the imaging device and all segments fit together in the field of view of the imaging device such that all of the region of space is mapped and monitored by the single imaging device. The present invention eliminates the need for several imaging devices to monitor high aspect ratio regions of space.

Abstract: An apparatus and method of stabilizing unstable shock waves on the surface of a body induce shock waves to form prematurely at a particular location on a surface of the body and fix that location such that shock waves will form consistently and persistently at that location on the surface of the body. Boundary layer flow separates from the surface of the body at that location and can be prevented from reattaching to the surface. Shock wave oscillations due to interactions with the separated boundary layer flow are prevented, thereby minimizing vibrations induced in the body. The apparatus has a flow accelerating surface and a discontinuity in the accelerating surface. The accelerating surface causes local fluid flow over the surface of the body to accelerate and prematurely and consistently form a shock wave at the point where the discontinuity is located.

Abstract: An apparatus and method of homodyne reception includes power divider circuitry for providing first and second signals from an input signal. Oscillator circuitry generates first and second oscillator signals. The first signal and second oscillator signal are mixed and the second signal and the second oscillator signal are mixed in first and second modulator circuitry, respectively, to provide first and second mixed signals which are further mixed together in image reject mixer circuitry. Amplifiers are used to amplify one of the signals before it is mixed with an oscillator signal and to amplify one of the mixed signals before it is mixed with the other mixed signal in the image reject mixer circuitry. In each of the mixing steps of the preferred embodiment is a filter which filters out spurs in the signals.

Abstract: An apparatus and method of stabilizing unstable shock waves on the surface of a body induce shock waves to form prematurely at a particular location on a surface of the body and fix that location such that shock waves will form consistently and persistently at that location on the surface of the body. Boundary layer flow separates from the surface of the body at that location and can be prevented from reattaching to the surface. Shock wave oscillations due to interactions with the separated boundary layer flow are prevented, thereby minimizing vibrations induced in the body. The apparatus has a flow accelerating surface and a discontinuity in the accelerating surface. The accelerating surface causes local fluid flow over the surface of the body to accelerate and prematurely and consistently form a shock wave at the point where the discontinuity is located.

Abstract: A measurement and control system for employment with a plurality of significantly spaced process access locations wherein a single cable extends in a loop by these access locations, and both ends of the cable are terminated at a central controller. The cable consists of a solid, conductive, outer housing and four spaced conductors within the housing, the housing being otherwise filled with a dielectric material. Data units are positioned at each access location, and each data unit is configured to supply and receive, or one of the other, discrete data by being coupled to the cable, two of the conductors of the cable furnishing power for the data unit, and the other two providing communications. Certain of the data units employ transducers to measure a single physical state. Outputs from these transducers, in analog form, are serialized, converted to digital data, cross-compared to determine off scaled readings, and the good readings averaged.