Abstract: An improved position detecting apparatus for detecting the position of an underwater moving body loaded with an inspecting device is provided. The apparatus is such that it makes it possible to perform inspection of a structure in water quickly, reliably and with high precision. The improvements reside in that the apparatus comprises a light source and a corner cube mounted on the underwater moving body in combination to serve as a target, a follower device, which includes a visual sensor for catching light emitted from the light source, for automatically following the target, an underwater argon laser length measuring instrument for measuring a distance between a length measuring head integrated with the visual sensor and the corner cube, and a detector device for detecting the position of the underwater moving body on the basis of an azimuth angle of the target obtained by the follower device, a reference of one side of a triangle and the measured distance.

Abstract: A velocity distribution measurement apparatus directs light at an object, detects scattered light from the object, photoelectrically converts the light and subjects it to signal processing to obtain velocity distribution characteristics of the object, by detecting a speckle pattern formed by interference between rays of light scattering from points on the object. The apparatus consists mainly of a laser beam source; an optical deflector for scanning the laser at a certain frequency; an optical system for projecting the light scanned by the deflector onto the object; a detector for detecting the speckle pattern; and signal processing means for analyzing detector outputs to establish the speckle pattern variations for each scanning frequency at which the optical deflector performs scanning, in order to obtain information on velocity distribution in the object. The optical system is easy to adjust, and measurement and processing can be accomplished in a relatively short time.

Abstract: A distance measuring device is provided with a plurality of comparators which are respectively connected to a plurality of light receiving elements for receiving light reflected from a subject. The plurality of comparators detect the levels of output signals of the light receiving elements. The comparators are supplied with reference voltages to be used for comparison with the output signals, the reference voltages being set different for each comparator according to the distance from whic the respective light receiving element receives light.

Abstract: A laser Doppler anemometer with at least two laser beams pass to a region of a fluid flow containing particles. The scattered light is frequency shifted by the Doppler frequency resulting from the flow speed. The construction is very compact and permits a high signal-to-noise ratio for the measurement signals. The laser beams consist of high-frequency pulses, the frequency of the pulse sequence of which is a multiple of the Doppler frequency.

Abstract: Three linear direction measurement sensors mounted adjacent to one another comprise a device for simultaneously measuring the directions of a plurality of optical targets. Four linear direction sensors distributed over at least two locations comprise a device for simultaneously measuring the three-dimensional positions of a plurality of optical targets.

Abstract: The range to an object is obtained by conveying light rays from the object through an afocal telescope to spatially displaced objective lenses that view the scene from two displaced points of view. The scene images from the objective lenses are focussed on two television sensors, respectively. The video frame from the TV sensors are digitized and stored in respective frame grabbers. A timing and logic circuit controls the television sensors and frame grabbers to alternately provide frames from the two television sensors to a monitor. The timing and logic circuit time shifts the output of one of the frame grabbers with respect to the output of the other frame grabber. A correlator responsive to the frame grabber outputs provides the correlation therebetween. The time shift required to bring the video images of the object into coincidence, at the correlation peak, provides a measure of the range to the object.

Abstract: Disclosed is a method for rapid and accurate qualitative and quantitative analysis of finishing agent applied onto the surface of a glass fiber substrate. This method comprises placing a glass fiber substrate to be tested in a Fourier transform infrared spectrophotometer equipped with a diffuse reflectance measuring device, irradiating said glass fiber substrate with infrared ray and carrying out qualitative analysis of finishing agent on the surface of the glass fiber substrate from wave number of infrared absorption peak produced at the irradiation and quantitative analysis of the finishing agent from intensity of the infrared absorption peak.

Abstract: The series wound, air core (SWAC) homopolar generator includes a pair of ls connected in series with a rotor having a pair of slip rings joined by conductive bars. To reduce eddy currents induced in the slip rings, their radius and axial length are chosen such that the circumferential and axial resistances of the slip rings fall in a bounded region wherein the axial resistance is minimized and the circumferential resistance is maximized.

Abstract: A fabric moisture detector and method is provided. The detector has a supt insulating structure, and a pair of electrodes, which have a pair of opposite faces separated by a gap of selective thickness, such as four inches or ten centimeters. The detector also has a current sensor, for measuring the current through the gap during the application of a relatively high voltage, such as about 10,000 volts to 60,000 volts for a ten centimeter gap. The voltage applied using a ten centimeter gap can be between about 1,000 volts per gap centimeter to 6,000 volts per gap centimeter. The process includes the steps of measuring the gap current during the application of the specified voltage, whereby a dry fabric or bare electrodes yields substantially no current and a wet fabric yields a peak current.

Abstract: A single-Schottky liquid crystal is disclosed in which a series of Schottky contacts are made on one side of a photoconductor substrate by a metal matrix mirror, with a doped semiconductor back contact electrode on the other side of the substrate. The light valve offers several operational advantages over MOS devices, and is easier to fabricate than double-Schottky light valves. It can be operated either in an AC mode or, by doping the liquid crystal ions, in a DC mode.

Abstract: A system in which the light of a single laser is used to both expose a hologram and to simultaneously measure the formation of the hologram in the recording material.

Abstract: Optical energy is conveyed through a region and is subsequently converted to electrical energy when it reaches the area of its intended use. Spatially multiplexed laser light is transmitted through an optical fiber to convey the energy through the area. Several light beams or several light beam paths may be used to convey a plurality of beams of light energy into an area either simultaneously or sequentially. Typically, two light beams enter the fiber at different angles of incidence, resulting in a first annulus of laser light that impinges on a first photocell and a second annulus of laser light that impinges on second photocell. This sequence continues alternately with the electrical outputs of the two photocells being coupled to a step-up transformer to provide electrical power for a system of interest, and or the energy being directed to a communication circuit for removing intelligence signals therefrom.

Abstract: A master/slave opto-electrical telephone communication system utilizes a single optical fiber line to transmit out to the subordinate or slave unit from the superior or master unit two light energy carrier waves of different wavelengths, one being modulated and the other unmodulated. At the slave station, the modulated wave is demodulated and translated into sensible signals and the unmodulated wave is modulated and retransmitted to the master station where it is demodulated and translated into sensible indicia.

Abstract: Optical power is supplied to a remote location and switched between conveon circuits for converting the optical power to electrical power to remotely power a system or device. Laser light is guided by a fiber optic to illuminate photovoltaic cells to produce the electrical power. The electrical current from the cells is made to alternate by switching the light between the cells and using a transformer to step up the voltage. This allows power to be supplied to a remote area without disrupting the existing electromagnetic fields in the area and where space and voltage requirements are limited such that the use of many photovoltaic cells is prohibitive.

Abstract: A method of indicating the state of charge of a battery is provided wherein a LED clock electrically connected to the battery operates each time current passes through the battery and stops when there is no battery current; the clock retaining the amount of time already passed so that resumed battery operation again activates the clock to continue counting.

Abstract: An infrared thermal monitoring system for use by a range or safety officer to monitor and record a tank gunnery training battle scene during poor visibility conditions, such as inclement weather and totally dark night time conditions. The system is comprised of readily available components which are used with the head assembly of a U.S. Army tank thermal sight (TTS) which converts an infrared image of battle scene into a visible image for display. The components are a charge coupled device (CCD) camera mounted on the head assembly for direct viewing of the visible image, a control console which controls the function of the head assembly and provides additional information to the output of the camera.

Abstract: A high voltage linear switch assembly is disclosed that uses a hollow quartz tube as the insulator, and houses the anode, cathode and switch within the insulator tube. The anode and cathode are fixed within the tube on opposite sides so that they do not make physical contact with each other. A chamber filled with either hydrogen or helium and a metal electrode screen act as the switch as follows. By separating the anode from the cathode the gas filled chamber normally acts as an open circuit. When a charge is conducted by the metal electrode screen, the gas in the chamber is ionized and provides a medium to provide electrical contact between the anode and the cathode.

Abstract: A device for inspection by eddy current methods of materials exhibiting cumferential conductivity. This device finds application for the inspection of filament-wound carbon fiber reinforced composites which do not usually have sufficient conductivity in the axial direction to allow inspection by conventional surface probes while still providing the desired resolution. This device is also useful in inspecting thick-walled circumferentially conductive materials, including metal, where their thickness would require a surface probe of such diameter as to be impractical.

Abstract: A TV seeker electronic color filter that has a three color striped solid te video sensor chip mounted in the optical path of a TV camera of a missile with the color filter stripes being manually selected by an individual to provide an optical response in portions of the spectrum to enable a target to be enhanced by the selection of the appropriate filter by an individual operator.

Abstract: Several gas-tight enclosures share a common optical cavity. The enclosures may be filled with neat gases or mixtures of gasses. The same gas or mixture, at the same or a different pressure, may occur in more than one enclosure. The gas or gasses in the various enclosures may be pulsed to lase in any desired sequence, simultaneously, or in any combination.