Abstract: The apparatus is an earth horizon crossing indicator used in a spacecraft attitude control system, which uses power from a self-contained battery rather than power from the spacecraft electrical system. The battery is typically of the lithium thionyl chloride type. This reduces the weight and complexity of the spacecraft attitude control system and allows the resources of the spacecraft electrical system to be used for other devices.

Abstract: A film is applied to a substrate in accordance with a predetermined pattern by applying a solution of a copolymer of fluoropolymers dissolved in a solvent onto the surface of the substrate; curing and annealing the solution to boil off the solvent and form a copolymer film on the substrate; depositing a thin metal film on the copolymer film; patterning the thin metal film by a photoresist etching process to expose the underlying copolymer film in accordance with the predetermined pattern; removing the exposed copolymer film so that the underlying substrate is exposed in accordance with the predetermined pattern; removing any remaining thin metal film; depositing the film to the remaining copolymer film and exposed substrate; then removing the remaining copolymer film and any film applied thereon by ultrasonic cleaning.

Abstract: The earth horizon sensor apparatus uses first and second linear sensor arrays of sensor elements, the first and second linear sensor arrays being staggered with respect to each other. The sensor elements are preferably pyroelectric elements for detecting the presence or absence of infrared radiation from the Earth and Space. A microprocessor is used to determine which of the sensor elements subtends the diffuse horizon gradient and the constant zero radiance of Space. The attitude of the spacecraft is thereby calculated.

Abstract: A process for making an infra-red detector array wherein an array of m * n first electrodes is formed on a substrate and a layer of plastic material having a polarization sensitive to infra-red radiation is deposited over the electrodes. The layer is partitioned into individual films each over an associated first electrode and second electrodes are positioned on the films on the side opposite to the associated first electrodes.

Abstract: The apparatus is a thermal detector which uses an active detector element and a compensator detector element, particularly in a voltage divider configuration. Radiation from a scene of interest impinges on the active detector element and radiation from an electronically modulated light source impinges on the compensator detector element.

Abstract: A thermal detector is made from a pair of electrodes and a plastic material disposed therebetween which material has a polarization sensitive to IR radiation. Preferably the detector is formed on a substrate with the plastic material being deposited by spin-casting. The material is a copolymer of TrFE and PVDF. The detector may be partitioned into an array of sensors and used in an apparatus wherein the image of an object is projected onto the array and a chopper is used to block the image from the sensors at regular intervals.

Abstract: The apparatus is a pyroelectric detector array with an optical filter. A plurality of pyroelectric detector elements are arranged on a common substrate and an optical filter is placed immediately adjacent to the pyroelectric detector elements. The optical filter includes a plurality of filter elements, each with a preselected optical passband. The optical filter is arranged so that radiation incident on a pyroelectric detector element passes through a respective unique filter element.

Abstract: A method and apparatus for mounting pyroelectric crystal elements and arrays on a molded plastic base. The molded plastic base includes a plurality of upwardly tapered plastic flexible legs which engage the pyroelectric crystal element or array at various points. The upwardly tapered plastic legs reduce to a nominal thickness of approximately 0.002 inches where they are fastened by epoxy onto the pyroelectric crystal element or array.

Abstract: The attitude of a satellite is determined by using an array of IR detectors receiving an image of space and the Earth. The detectors are positioned so that at least one detector monitors the radiance from the Earth's horizon and a second detector monitors a region of the Earth adjacent to said horizon. The output of the first detector is compensated for variations in the radiance of the Earth by using the output of the second detector.

Abstract: The attitude of a satellite is determined by using an array of IR detectors receiving an image of space and the Earth. The detectors are spaced so that at least in a central zone, the sun will not enter the optical field of more than one detector. The signals from each detector are monitored and if a signal is very high, indicating that the sun's image is falling on the detector, that signal is ignored.

Abstract: A detector apparatus uses two scanners on the right of way for monitoring the wheels of a moving train . The scanners scan the wheels transversely to the tracks along a common axis and generate wheel temperature signals. The signals corresponding to the wheel bearing end caps or housing lids indicative of the wheel bearing temperatures are separated and analyzed so that the apparatus can detect and indicate both hot wheel and hot bearing conditions.

Abstract: An on-board hot bearing detector system includes a microprocessor and heat sensors mounted on the train cars for sensing the bearing temperatures. Diagnostic circuitry is also provided to monitor the sensors and detect if a sensor is open or short. Additionally, the train line is controlled by the microprocessor and is provided with a current limiting device for protection against large currents in case of a short.

Abstract: A railroad car wheel transducer includes a coil positioned along a rail of a track. The presence of a wheel proximal to the coil causes basic electrical characteristics of the coil, such as its inductance and Q factor to change, which is sensed and used to generate a coil signal. A calibrating circuit monitors the coil characteristics to compensate for long term drifts.

Abstract: A train analysis system for analyzing a wheel condition such as wheel bearing temperature includes circuitry for identifying the wheels of a railroad car, circuitry for averaging the condition of each wheel of a car, and circuitry for establishing a threshold level for said condition, dependent on said averaging. When a wheel cannot be identified, a threshold level is set which is below the maximum level for identified wheels.

Abstract: A detector for detecting hot wheels or bearings on a railroad car includes an infrared sensor supported within a detector by a sensor housing. Elastic balls are disposed in the housing to absorb shocks generated by a train passing the detector.

Abstract: A temperature sensor assembly for monitoring railroad car wheels includes an array of temperature detectors arranged to generate a temperature profile of the wheel. The array may be formed integrally with imaging elements and signal conditioning elements on a single IC chip. The assembly may be arranged to monitor the wheel either transversely or in parallel to the direction of wheel movement.

Abstract: The present invention relates to bearing defect detectors and in particular to an acoustic system for detecting defects in the bearings of moving railroad cars and identifying the location of these defects.

Abstract: This invention relates to a device for monitoring the temperature of the wheels of passing railroad cars. More particularly, this device includes a self-calibration function wherein a predetermined heat source is attached to the device, a fixed amplifier amplifies the resulting electric signal so as to generate a signal comparable in magnitude to that generated by a passing train, a variable gain amplifier further amplifies the signal, and the resulting signal is converted to a digital signal. The digital signal is used as a signal to the feedback input of a variable gain amplifier. In response to the digital signal, the variable gain amplifier adjusts its gain until the feedback signal reaches a predetermined value.

Abstract: This invention relates to the testing of apparatus used for on-line acoustic detection of bearing defects, particularly in railroad applications. A loudspeaker on each side of the section of track, in response to a microprocessor, generates simulated acoustic signatures characteristics of various bearing defects. The microprocessor additionally sends corresponding simulated train speed signals to the apparatus. The invention monitors the apparatus for the appropriate alarm signal.