Abstract: An optical safety apparatus for use in a vehicle having a tension controlled braking mechanism is disclosed herein. Included in the safety apparatus is a lamp means for emitting an optical braking signal and a mounting means for securing the lamp means to the vehicle. A switch means electrically connected to the lamp means controls emission of the braking signal in response to engagement of the braking mechanism. Included in a specific embodiment is a trifunctional lamp means for emitting an optical braking signal, for reflecting incident radiant energy and for generating an optical safety signal.

Abstract: A method and system is disclosed which provides precise multi-function digitally implementable modulation for a communication system. The invention provides a modulation signal for a communication system in response to an input signal from a data source. A digitized time response is generated from samples of a time domain representation of a spectrum profile of a selected modulation scheme. The invention generates and stores coefficients for each input symbol in accordance with the selected modulation scheme. The output signal is provided by a plurality of samples, each sample being generated by summing the products of a predetermined number of the coefficients and a predetermined number of the samples of the digitized time response. In a specific illustrative implementation, the samples of the output signals are converted to analog signals, filtered and used to modulate a carrier in a conventional manner.

Abstract: An inertial measurement unit which provides three axis acceleration and angular turning rate detection with a cubical magnetically suspended sensor mass disposed within a cubical outer assembly. The sensor mass is free to move mechanically independent from the outer assembly. The sensor mass has a plurality of sensing and suspension elements of particular orientation on a selected plane for each axis of detection which face a corresponding set of sensing and suspension elements respectively on interior surfaces of said outer assembly. The sensing elements are advantageously cross-coupled to minimize cross-axis sensitivity. The invention utilizes several servo-control loops of conventional design to process outputs from the pickoffs and maintain the sensor mass in proper orientation.

Abstract: Apparatus for catching fluid leaking from underneath a vehicle is provided. The invention includes means for supporting a receptacle relative to a vehicle which is leaking fluid in a position whereby the fluid flows into the receptacle. In a preferred embodiment, the means for supporting the receptacle is a magnet which is bonded to the receptacle. A specific embodiment includes material for absorbing the fluid after it has flowed into the receptacle. In the illustrated embodiment, the material is a foam. The specification sets forth other aspects of the invention designed to reduce weight, reduce cost, improve strength and improve overall performance.

Abstract: A modulator system for converting a three-channel input microwave signal to a single-channel output microwave signal is formed of two microwave sections which are joined together at both their inputs and their outputs by hybrid circuits, one of which serves as a power divider and the other which serves as a power combiner. Each of the microwave sections includes a pair of couplers which are joined by a Faraday rotator. First and second microwave input signals are applied to a first port of an input coupler in each of these sections. A third microwave signal is connected by the hybrid divider to a second input port in the input couplers of each of the microwave sections. Polarization of the third signal is vertical and is maintained through the two sections. Polarization of the first and second signals is horizontal and is maintained through the two sections.

Abstract: A thin-line heading sensor is disclosed having an outside diameter of less than an inch which is accurate to within 1.degree. of arc. The invention includes a magnetic wheel having a reflective multifaceted perimeter. The facets are optically coded for identification. When the wheel is illuminated by a collimated beam of light, a beam is reflected onto an array of photodetectors. The photodetectors are coupled with an electronic circuit which decodes the position and pattern of illumination to determine the position of the magnetic wheel.

Abstract: An optical system is disclosed which incorporates a color selective prepolarizer to improve contrast and reduce stress induced birefringence while allowing a blue mirror to be used to enhance the projected image. The invention includes a source lamp for providing a first beam of unpolarized white light energy; a prepolarizing beam splitter which extracts from the first beam, second and third beams. The second beam contains undesirable color components of a first polarization state, which are removed from the system by reflection to an optical dump. The third beam includes prepolarized light of one color and the first polarization and white light of the second polarization. A main polarizing prism is provided for splitting the third beam into fourth and fifth beams having the first and second polarizing states respectively. The main prism effectively directs the white light to the light valve where it is modulated and returned to the main prism for projection in the conventional manner.

Abstract: This invention provides a unitary oil coupled optical arrangement for color selective prepolarization of the light incident upon two light valves. The optical arrangement is immersed within a single tank. It includes dichroic filters which act on polarized light from a light source which has been polarized into two beams by passing through and being reflected from a prepolarizing optical thin film stack. The first dichroic filter provides light of a first color and a first polarization while the second dichroic filter provides light of a second color and a second polarization. The light from each of the filters is then combined into a single beam by a thin film polarization-selective beam combiner prior to being applied to the main polarizing prism. The main prism then passes light of a first polarization and a first color to a first light valve and light of the second polarization and a second color to the second light valve in a conventional manner.

Abstract: A first color selective beam splitter is provided for splitting light from a source into first and second beams, the first beam being blue and the second beam having red and green color components.A second beam splitter is provided for directing light of the first beam to a blue liquid crystal light valve. The light valve modulates the polarization of the light in the first beam and returns it to the second beam splitter which converts the modulations of polarization to modulations of intensity in the conventional manner and reflects it to a first projection lens.A third beam splitter is provided for splitting the second beam into third and fourth beams having first and second polarization states, respectively. The third beam is reflected to a red filter. The fourth beam is transmitted through a green filter.The output of each filter is a substantially monochromatic beam of a single polarization state. The filter outputs are recombined into a single beam which illuminates a fourth beam splitter.

Abstract: A full color high contrast image projection system with oil coupled dichroics and a single projection lens is disclosed. The invention includes a unitary optical tank in which a prepolarizer and dichroic separators are mounted in fixed alignment relative to a main polarizing prism. The prepolarizer acts on the incident light from a source to polarize the green light and reflect the S component out of the system. The red and blue components are transmitted unchanged. The main polarizer is mounted at a 90.degree. twist relative to the prepolarizer so that it reflects the green light to a first light valve via a first dichroic separator. The polarized red and blue components are transmitted to second and third light valves via a second dichroic separator. The light valves modulate the polarization state of incident light before returning it to the second beamsplitter. The second beamsplitter then recombines the individual beams into a single output beam.

Abstract: A tri-mode spherical cavity microwave filter comprising two tandemly disposed generally spherical bodies each of which defines a spherical cavity which supports three identical, mutually orthogonal modes of electromagnetic energy, a cavity coupling aperture connecting the cavities, a plurality of cavity tuning holes, and a plurality of coupling tuning holes. One of the spherical cavities has an input aperture, and another has an output aperture. The cavity tuning holes and coupling tuning holes are adapted to receive cavity tuners and coupling tuners, respectively.

Abstract: An optic receiver capable of detecting the angle of incidence of optical energy in a plurality of fields of view relative to an airborne frame of reference. Incoming rays are reflected by surfaces arranged at predetermined angles relative to an input aperture so as to reflect rays in predetermined fields of view into parallelism with the receiver axis and ultimately to a line image at an output aperture. Power distribution along the line image varies with the azimuth of the target reflection. Computation of target azimuth from the power distribution along the line image is facilitated by photodetectors mounted on the element and associated electronic circuitry.

Abstract: An improved low-cost microwave receiver is disclosed. The receiver is intended for use in the Multipoint Distribution Services (MDS) for the reception of television signals transmitted in the 2 to 2.5 GHz region. The receiver of the present invention is of the single-conversion superheterodyne type utilizing printed circuit and microstrip transmission line construction. Printed circuit board and microstrip transmission line construction permits low-cost fabrication without machined resonant cavities or waveguide components.

Abstract: An improved laser pumping system is provided which utilizes optic fibers configured in a fan-in arrangement and an array of light emitting diodes or diode lasers to which the optic fibers are connected for concentrating light energy on a lasing medium. The improvement is an increase of the amount of light energy that can be applied to the laser within a fixed volume.

Abstract: A processor for operating on video and azimuth signals from a radar system having an antenna which scans in azimuth. The processor enhances the signal-to-noise ratio of the video signals while imposing thereon a substantially constant azimuth delay error.The processor includes a first circuit for forming and storing a count indicative of the video signal history in each range zone. The processor also includes a second circuit for generating and removing a flag signal indicative of azimuth leading and trailing edges respectively of a target pulse in the video signal. A gating circuit is included to pass video signals, for a given range zone, to an output terminal during the presence of a flag signal associated with the zone.

Abstract: An improved photodector which in utilizing a low noise load network instead of a resistor has the advantages in signal-to-noise ratio of a large load resistance without the deleterious effect on response time. The circuit includes a conventional photodiode with an operational amplifier at its output. The load network is disposed in the feedback path of the operational amplifier. It consists of a second operational amplifier, a fixed resistor and a variable resistor.

Abstract: An auto-alignment system for high energy lasers wherein a low energy reference beam is provided at the vertex of a primary mirror that is grated to diffract a low energy holographic replica of the high energy beam. A photodetector based servo-control system compares the line-of-sight of the reference beam to that of the low energy replica and generates control signals which actuate a beam steering mirror to reposition the main beam. The servo-control system also includes a wavefront sensor. This sensor analyzes the wavefront profile of the low energy replica and generates control signals which actuate a deformable mirror to correct spurious wavefront aberrations.

Abstract: An optic receiver capable of detecting the angle of incidence of optical energy relative to an airborne frame of reference. Incoming reflected rays are reflected by a one piece detector element into a line image. Power distribution along the line image varies with the azimuth of the target. Computation of target azimuth from the power distribution along the line image is facilitated by photodetectors mounted on this element and associated electronic circuitry.

Abstract: A system is disclosed for frequency compensation and amplitude compression of signals from a scene having targets which radiate infrared energy. The system uses at least two combinations, where each combination consists of an operational amplifier and a variable resistance element. These combinations are electrically coupled to each other. A circuit connected to one of the amplifiers provides high frequency compensation for radiated energy by small targets in the infrared scene. The system also utilizes a reference source which is coupled to the input of another of the amplifiers.