Abstract: A film advancement indicator which includes an optical sensor 21 that detects the rotational movement of a disc 18 that rotates only when the film 14 advances. When the film 14 does not advance, an indicator light 29 is activated. A counter 26 is included in the electronic circuit to determine the number of film frames advanced.

Abstract: A broadband megahertz range electrostatic acoustic transducer for use in a liquid environment. A liquid-tight enclosure 11 which includes a metallic conducting membrane 18 as part of its outside surface has a means 19 inside the liquid-tight enclosure for applying a tension to the membrane and for mounting an electrode 23 such that the flat end of the electrode is approximately parallel to the membrane. The invention includes structure and a method for ensuring that the membrane 18 and the flat end of the electrode 23 are exactly parallel and a fixed predetermined distance from each other.

Abstract: A large volume multiple-path nuclear pumper laser which has improved characteristics over previous cylindrical nuclear pumped laser systems. Large volumes of gas are excited by using internal high reflectance mirrors that are arranged so that the optical path crosses back and forth through the excited gaseous medium. By adjusting the external dielectric mirrors of the laser, the number of paths through the laser cavity can be varied. Output powers have been obtained that are substantially higher than the output powers of previous nuclear laser systems.

Abstract: This invention is an electrostatic conductive fiber detector for use in detecting, counting and measuring the length of fibers down to O.1 mm and below with increased accuracy and reliability over prior art devices. It can be used for detection of fibers suspending in a flowing gas, in a nonflowing gas, or in a vacuum and its accumulated counts over a period of time is essentially unaffected by velocity of the fibers being detected.

Abstract: An annular momentum control device (AMCD) 11 is operated in a strapped down position on a spacecraft. The signals from the position sensors 18 and 19 at the several AMCD magnetic bearing stations a, b, and c are applied to computers (FIGS. 4 and 5) which compute the angular rate about first and second axes in the plane of the AMCD rim 12 and compute the linear accelerations along the first and second axes and along a third axis perpendicular to the first and second axes.

Abstract: This invention relates to the use of a standing acoustic wave charge storage device 11 as an image readout device. A frequency f.sub.1 22 is applied to the storage transfer device to create a traveling electric field in the device in one direction along a straight line. A second frequency f.sub.2 23 which is a harmonic of f.sub.1, has the same amplitude as f.sub.1, and is phase stable with f.sub.1 is applied to the charge transfer device to create a traveling electric field in the opposite direction to the first traveling electric field. Consequently, a standing wave (FIG. 2) is created in the charge transfer device along the straight line. When an image 25 is focused on the charge transfer device, light is stored in the wells of the standing wave. Thereafter when the frequency f.sub.2 is removed from the device, the standing wave tends to break up (FIG. 3) and the charges stored therein are moved to an electrode 18 which is connected to an output terminal 19.

Abstract: An aircraft pitch attitude stabilization system that utilizes an engine pressure ratio signal to cancel pitching moments due to changes in engine thrust. The changes in the engine pressure ratio signals which result from thrust changes are used to generate a pitch stabilization signal that is combined with other pitch control signals to automatically counteract pitching moments resulting from the changes in engine thrust.

Abstract: A broadband adaptively controlled polarization separation network. Two transmitted signals vertically and horizontally polarized are received as elleptically polarized signals. One of the two received elliptically polarized signals is automatically adjusted to make it linear and thereafter automatically adjusted to make it vertical. If the other signal does not have any vertical polarization on it then the two signals are easily separated and nothing else is needed. However, if there is any vertical polarization on the other signal this invention provides for separating the resulting crosstalk between the two signals. This is done automatically by the use of two sets of crosscouplers which couple a single line to the other line to complete the polarization decoupling operation.

Abstract: A device for providing acceleration cues to the helmet of a simulator pilot. Pulleys are attached to both shoulders of the pilot. A cable is attached to both sides of the helmet and extends through the pulleys to a takeup reel that is controlled by a torque motor. Control signals are applied to a servo system including the torque motor, the takeup reel and a force transducer which supplies the feedback signal. In one embodiment of the invention the force transducer is in the cable and in another it is in the takeup reel.

Abstract: A pilot controlled stability control system that employs direct lift control (spoiler control) with elevator control to control the flight path angle of an aircraft. A computer on the aircraft generates an elevator control signal and a spoiler control signal, using a pilot-controlled pitch control signal and pitch rate, vertical velocity, roll angle, groundspeed, engine pressure ratio and vertical acceleration signals which are generated on the aircraft. The direct lift control by the aircraft spoilers improves the response of the aircraft flight path angle and provides short term flight path stabilization against environmental disturbances.

Abstract: A laser velocimeter that determines the direction of movement of particles. A laser produces a transmitted beam that illuminates the volume under investigation. The backscattered light is divided into two equal intensity beams. A first part of a sample of the transmitted beam is mised with one of the two equal intensity beams and applied to a first photodetector. A second part of the sample is phase shifted by 90.degree., mixed with the other of the two equal intensity beams and applied to a second photodetector. The output of the first photodetector is phase shifted by -90.degree. and then multiplied with the output of the second photodetector to produce a signal indicative of direction of movement.

Abstract: A phase insensitive ultrasonic transducer which includes a CdS crystal that is annealed for a selected period of time and at a selected temperature to provide substantially maximum acoustic attenuation at the operating frequency of the transducer. Two electrodes are attached to the crystal with amplifier means and a signal processing system connected to one of the electrodes to provide an ultrasonic receiver.

Abstract: An energy conversion apparatus is disclosed in which a stator, fixed relative to a watertight housing, is coupled to a rotor by a helical spring which suspends the rotor from the housing. Natural turbulence of a fluid, such as water or air, causes acceleration of the housing, and hence, acceleration of the stator. Inertia of the rotor, coupled to the stator through the helical spring and the housing, causes relative motion, both longitudinal and rotational, between the stator and the rotor, the rotational motion between the rotor, and the stator being used to generate electrical current.

Abstract: Apparatus for indicating the instantaneous angular deflection of an object about a selected axis without mechanical contact with the object. Light from a light source is transmitted through a first flat refractor to a converging lens which focuses the light through a second flat refractor onto a differential photocell. The first flat refractor is attached to the object such that when the object is deflected about the selected axis the refractor is also deflected about that axis. The two flat refractors are identical and they are placed an equal distance from the converging lens as are the light source and the photocell. The output of the photocell which is a function of image displacement is fed to a high gain amplifier that drives a galvanometer which rotates the second flat refractor. The second refractor is rotated so that the image displacement is very nearly zero making the galvanometer current a measure of the deflection of the object about the selected axis.

Abstract: A system is disclosed for detecting the laminar to turbulent boundary layer transition on a surface while simultaneously taking pressure measurements. The system uses an accelerometer for producing electrical signals proportional to the noise levels along the surface and a transducer for producing electrical signals proportional to pressure along the surface. The signals generated by the accelerometer and transducer are sent to a data reduction system for interpretation and storage.

Abstract: Apparatus for remotely measuring and accessing water status relative to snow and glacial melt, surface runoff, rainfall, evaporation, flow rate, and soil moisture. A radar target located at a selected location on the surface of the earth is designed to collect water and render its cross-sectional area variable as a function of the height of the water level within the target. The target is remotely monitored by an orbiting or airborne synthetic aperature radar. The target appears as a bright spot embedded within the radar image. The target brightness is indicative of the height of the water level within the ground located target.

Abstract: A transducer that combines a noncontacting displacement probe with a self-contained target. The target is held in position against a vibrating surface by a housing which also supports the noncontacting probe. The target vibrates with the surface and the probe senses the vibrations of the target.

Abstract: A seat cushion for providing realistic acceleration cues to an aircraft simulator pilot. A plurality of contiguous seat cushion compartments with each including an air cell with a non-compressible surface underneath the air cell are provided with apparatus for separately controlling the pressure in the air cells. Apparatus are provided for initially controlling the air pressure in the air cells to allow the two main support areas, the tuberosities, of the simulator pilot to touch the non-compressible surface and thus begin to compress the flesh near these areas. Thereafter during a simulated flight apparatus are provided for controlling the air pressure in the cells to simulate the events that occur in a seat cushion during actual flight.

Abstract: Apparatus for providing accurate pointing of instruments on a carrier vehicle and for providing isolation of the instruments from the vehicle's motion disturbances. The apparatus includes two assemblies, with connecting interfaces, each assembly having a separate function. The first assembly is attached to the carrier vehicle and consists of an azimuth gimbal and an elevation gimbal which provide coarse pointing of the instruments by allowing two rotations of the instruments relative to the carrier vehicle. The second or vernier pointing assembly is made up of magnetic suspension and fine pointing actuators, roll motor segments, and an instrument mounting plate around which a continuous annular rim is attached which provides appropriate magnetic circuits for the actuators and the roll motor segments.

Abstract: An electrochemical detection device for detecting micro-organisms. A standard pH reference electrode and a platinum cathodic electrode are positioned in a container with suitable nutrient medium for microbial growth plus the sample to be tested. The two electrodes are connected to electronic circuitry including an up/down counter which counts up for the first 80 minutes after a test has been initiated. Then the potential between the two electrodes is tracked by the electronic circuitry and after there is a change of 10 mv a signal is sent to the up/down counter to cause it to reverse its count. Thereafter when there is a additional 20 mv change in the potential between the two electrodes another signal is sent to the up/down counter signalling it to stop. The resulting count on the counter is equal to the length of time for the inoculum to begin the production of measurable amounts of H.sub.2 after inoculation. This length of time is indicative of a endpoint.