Abstract: A method of calibrating a video system, which includes a video camera hav a lens for viewing a scene and a video recorder for recording the scene on video tape, to determine both vertical and horizontal angular dimensions of the scene. The video camera lens is focused for infinity and an image of an illuminated reticle pattern of known angular shape and size formed at infinity is projected into the video camera lens and recorded on the video tape by the video recorder. The optical device used to project the reticle pattern image is similar to known projection systems of certain types of gunsights.

Abstract: The invention comprises a variable linear resistor. It comprises a first plate having a recessed area cut into one face and a second plate parallel to and facing the face of the first plate with the recessed area. A length of elastic tubing is disposed in the recessed area. The distance between the two plates is adjustable, and this allows for the compression of the elastic tube.

Abstract: Two sensors are mounted a distance "a" apart near the muzzle of a gun barrel. The first position sensor generates a signal which initiates a binary count, upward from zero at a clock frequency, when the projectile passes the first point. The second sensor generates a signal which reverses the direction of count, at a preselected submultiple of the clock frequency. The time required to return the count to zero is an integer multiple of the time required for the projectile to travel from the first sensor to the second sensor. Thus, the distance that the projectile travels will be an integer multiple of the distance "a" between the sensors. The velocity of the projectile remains relatively unchanged over the specified distance. The signal that is generated when the counter returns to zero may be used to trigger a monitoring device located at the specified point in front of the muzzle when the projectile passes that point.

Abstract: A temperature-compensated Bourdon tube gauge for indicating a parameter of a pressurized fluid, including a support structure, a Bourdon tube having an open fixed end receiving the fluid and a free closed end carrying an indicating member, a dial member carrying a parameter scale disposed along the path of motion of the indicating member, and a temperature-responsive element for moving the dial member in accordance with a sensed temperature such that the indicating member indicates the fluid parameter on the dial member scale. The temperature-responsive element comprises a bimetallic element connected between the support structure and the dial member. The bimetallic element may be connected to the dial member by a lever having a "variable fulcrum" which varies along the length of the lever in accordance with the shape of a cam with which the lever is maintained in contact.

Abstract: A fluidic complementary gain changing circuit has three laminar proportio amplifiers, one of which supplies fluid pressure streams to the other two. The latter amplifiers have substantially identical geometries and complementary gain curves at any given supply pressure, relative to a gain changing signal constituting a bias pressure applied to control ports of the first amplifier. A differential input signal supplied to the control ports of the two complementary amplifiers modulates the supply streams traversing those amplifiers and results in concurrent high and low gain complementary signals at the respective outlet ports of the overall circuit. Variable resistance elements permit calibration of the circuit.

Abstract: A method and apparatus for detonating an explosive in response to the dettion of a remote explosive without damaging any components positioned intermediate the two explosives. An impact switch having contact elements that permanently interlock when activated is positioned adjacent to one of the explosives. A power supply is connected to the impact switch, and the output from the power supply is connected to the detonator for the second explosive. When the first explosive is detonated, the contact elements of the impact switch close, permanently interlocking. This completes and activates an electrical circuit with the power supply that sends current to the detonator of the second explosive to initiate detonation of the second explosive.

Abstract: A mechanism for compensating an underwater transducer for the ambient hydrostatic pressure. The transducer housing includes a quantity of liquid which may be vaporized in the housing volume. The relative volumes of vapor and liquid depend on the temperature, pressure and type of liquid used. A small heater in the liquid increases the temperature of the liquid so that the pressure of the vapor increases and counteracts the increase in hydrostatic pressure at greater depths. The liquid chosen should have a high critical pressure relative to the operating pressure of the transducer.

Abstract: Method and apparatus for filtering high data rate signals, using a digital type filter, without requiring an analog-to-digital converter or the multiplicaton of digital signals. The incoming signal is wideband filtered and then hard limited to produce a constant amplitude signal having either a first or second instantaneous value. The constant amplitude signal is periodically sampled and stored in a multi-bit digital shift register as logic 1 or 0 signals. In one embodiment, the logic 1 or 0 signals stored in the shift register bits are periodically read out, multiplied by respective weighting constants, and summed to provide a filtered analog output signal. In another embodiment, the combination of logic 1 and 0 signals stored in the shift register are periodically sampled and used to address a memory, which outputs a digital signal which is the calculated value of weighted sum for that shift register combination.

Abstract: The present gun silencer includes an internal cardioid-shaped cavity which utilizes the principles of wave mechanics to attenuate the sound of a gun firing without contacting the projectile. The shock wave from a firing is totally internally reflected thereby confining and attenuating the sound from a gun firing. The silencer cavity is shaped in a manner guiding and concentrating shock waves from a gun firing to an exit port at which sound-absorbing material is present.

Abstract: Presented is a fluid property measuring device which can be used to measure he viscosity, the density, the volumetric flow rate, and the mass flow rate, of a fluid without using moving parts. The fluid property measuring device comprises a linear fluid resistor, a nonlinear resistor, and a linear, fluid property independent, volumetric flowmeter, Two nonlinear resistors, or two linear resistors, may be used instead of a linear and nonlinear resistor. The linear, fluid property independent, volumetric flowmeter comprises a fluidic negative feedback oscillator in fluid connection with a fluidic buffer laminar proportional amplifier.

Abstract: A reflecting asphere of revolution for reflecting light radiation having a wavelength in the range from 0.2 microns to 10 microns, emanating from or passing through a focus into an omnidirectional planar or conical fan beam of uniform thickness. The reflecting surface is generated by rotating an outer segment of a parabola about a line intersecting the parabola axis at its focus. In one application, this reflecting surface is used to equally disperse optical power emanating from the end face of an optical fiber to a plurality of solar cells. In another application, two of these reflecting aspheres of revolution are utilized to create an annular zone in a system for detecting objects, such as aircraft, entering the annular zone. Folding mirrors may be utilized to make systems using this reflecting asphere of revolution more compact. Also, truncated conical reflecting surfaces may be used with these reflecting aspheres of revolution to generate certain beams, such as annular cylindrical beams.

Abstract: A high efficiency diode detector for detecting low amplitude signal levels. A junction diode is biased by a stable current source to operate in a substantially square law region of the diode. A signal source having an impedance much less than the diode forward resistance in the square law region is connected to drive the diode. Signal levels in the 18 MV rms range are detected at efficiencies approaching 20%.

Abstract: A technique for reducing cross-polarized signals in the axis of four-port al-polarized antennas. The resulting lower cross-polarized signals reduce a tracking antenna's susceptibility to tracking errors and to breaklocks. Some energy from the transmission line connected to the (V) port is coupled, after proper attenuation and phase adjustment, and transmitted through the (H) port, thereby nulling out the (V) cross-polarized pattern.

Abstract: The invention involves the design of a piezoelectric pressure transducer d for measuring pressure-time characteristics in gun tubes during the propellent ignition and burning process. The transducer utilizes one or two Z-cut tourmaline crystals as the piezoelectric pressure sensing element which produces a finite amount of electrical charge for a given change in pressure. The tourmaline crystals are incapsulated in a mechanical fixture which provides means for mounting in the gun tube, electrical terminals for connecting to signal conditioning and recording instrumentation, and insulators for electrically insulating the transducer from the weapon ground. A needle valve is also incorporated in the transducer which provides means for replenishing the thermal protecting material around the crystal assembly without removing the transducer from the weapon.

Abstract: A system for manually setting a timing value of an electronic fuze for an artillery projectile prior to firing without tools or electric power, and for displaying the set timing value in standard decimal format. Two adjacent setting rings, disposed about the outside of the fuze housing, are interconnected together with the housing so that one ring rotates with the other ring when the other ring is manually rotated in one direction about the housing axis, but is prevented from rotating when the other ring is rotated in an opposite direction about the housing axis. Each ring carries a plurality of numbers disposed about its outer periphery such that one of the numbers is axially aligned with an indication mark on the fuze housing at each setting of the ring. The two series of numbers are oriented laterally so that the two numbers aligned with the indication mark constitute the desired timing value.

Abstract: Method and apparatus for modulating coherent radiation generated by an orotron in accordance with a low voltage control signal applied to the diffraction grating to vary the grating-to-cathode voltage from the cathode-to-collector voltage over a selected voltage range determined by the maximum and minimum values of the control voltage. For amplitude modulation, the grating-to-cathode voltage is varied within a voltage range between a lower voltage at which the orotron output power starts to fall abruptly and a cutoff voltage at which coherent radiation ceases. For frequency modulation, the grating-to-cathode voltage is varied within a voltage range, including the point of maximum power output, where there is a minimum change of output power with a change in the grating-to-cathode voltage.

Abstract: Apparatus to simulate supersonic high altitude flight for air driven eleccal generators. First and second air-tight chambers are provided, as are means for evacuating the chambers to a preselected pressure. The air driven generator has both air inlet means and air outlet means. The air inlet means of the air driven generator is in fluid communication with the second air-tight chamber, and the air outlet means of the air driven generator is in fluid communication with the first air-tight chamber. Adjustable orifice means are provided. Valve controlled air inlet means for allowing air to enter the second air-tight chamber through the adjustable orifice means are also provided.

Abstract: An apparatus for automatically determining various stresses measured by a rectangular strain gage rosette. The apparatus receives signals from the rosette and provides signals representative of the maximum principal stress, the minimum principal stress and the maximum shear stress, the peak maximum principal stress, the minimum principal stress at the instant when the maximum principal stress is peaking, and the peak value of the shear stress. A first analog signal processor provides stress signals representative of the maximum principal stress, minimum principal stress and maximum shear stress for each instantaneous input signal amplitude from each arm of the strain gauge rosette, and a second signal processor receives the stress signals and provides output signals representative of the peak maximum principal stress, minimum principal stress at the instant of peak maximum principal stress, and peak maximum shear stress.

Abstract: A method and apparatus for increasing the power output and efficiency of an orotron generating near millimeter wavelength radiation. In accordance with a theory of orotron operation described herein and confirmed experimentally, the ribbon-like electron beam utilized in the orotron has a very high current density to effect a large increase in orotron output power and efficiency due to space-charge effects in the beam. In the preferred embodiment, the high density electron beam is generated by a closely-packed rectangular array of field-emission cathodes.

Abstract: A reserve battery which includes a plurality of series-connected battery cells which are simultaneously filled with electrolyte from a reservoir through a like plurality of filling conduits formed of electrically-insulating material and connected respectively between the reservoir and the cells. In one embodiment, the cross-sectional area of each filling conduit is several orders of magnitude smaller than the area of each cell electrode active surface and the length of each filling conduit exceeds the square root of the filling conduit cross-sectional area by at least two orders of magnitude, to thus minimize intercell short circuits.