Abstract: A panoramic view of the world surrounding a stationary mast of a submarine is provided by a plurality of small windows disposed circumferentially around the mast and a corresponding plurality of lenses for imaging the fields of view thereof onto coherent fiber optic image bundles. The fields of view of the lenses overlap to provide a complete panoramic view. The exit ends of the image guides are arranged to form a polygonal opening so that a replica of the panoramic view is provided within the opening. A mirror or prism rotating within the opening scans the view replica and directs the scanned image to a stationary television camera. A derotating prism in the path of the directed scanned image rotates at one-half the angular displacement of the image director to compensate for rotation imparted to the scanned image by the image director.

Abstract: Performance of an inertial navigation system (INS) corrected with GPS position data is enhanced with the addition of a filter that smooths the GPS-INS position difference data and couples the smoothed data to the INS position data. Difference data provided to the filter is edited to eliminate GPS-INS position data that excceeds a predetermined level. Performance is further improved by applying position resets from the INS Kalman filter in a ramp like manner.

Abstract: A liquid level and weight sensor utilizes a pressure sensor of any type positioned at the base of the liquid or weight. A second pressure sensor is positioned external to the liquid or weight to measure the ambient pressure. Ambient pressure is subtracted from the total pressure indicated by the base positioned pressure sensor to determine the actual pressure exerted by the liquid or weight on the base positioned sensor. The actual pressure is then utilized in the calculation of liquid level or weight. The determination of liquid level requires that both the pressure and density of the liquid be known. When the density of the liquid is not known, a third pressure sensor is inserted in the tank at a known level above the first. The differential pressure and differential level are determinative of the liquid's density.

Abstract: The rudder angle indicator system utilizes a low cost potentiometer coupled to the rudder to provide a signal proportional to rudder angle. A stepper motor positions, in open loop arrangement, the dial of a rudder angle indicator, such as a large three-faced rudder angle display, in accordance with the potentiometer signal. An active sector tab and sensor are utilized to provide a signal in accordance with when the indicator is in the active sector of the display so as to minimize the search for the indicator zero index tab.

Abstract: A true predicted area of danger providing a preselected miss distance between an intruding vehicle and own ship is provided. A miss distance circle, having a radius equal to the desired miss distance, is generated about the initial position of the intruding vehicle and the relative coordinates and distances from own vehicle of selected points on this miss distance circle are determined. Points of own vehicle intercept of these selected points are established and a smooth curve is drawn through these points to provide the boundary of the predicted area of danger.

Abstract: An instrument mounting apparatus includes a bracket into which the instrument is inserted, a washer which slides over the instrument and dimensioned to hold the instrument, and a nut which also slides over the instrument. The bracket has key slots for accepting keys extending from the washer and has threads on the outer surface which mate with threads on the inner surface of the nut. Radial slots in the nut permit the insertion of a rod for torquing the nut tight to the bracket, while tapped channels are provided for a inserting a set screw into the one most convenient.

Abstract: A method and apparatus for determining from a moving observer the location, in terms of latitude, longitude, altitude, and velocity, of a stationary or moving radar emitting a pulsed or continuous-wave signal. The moving observer extracts from the radar signal significant electronic support measures (ESM) parameters, including frequency, pulse repetition interval, and pulse width, and determines from those parameters whether a radio frequency (RF) or pulse repetition frequency (PRF) measurement technique is appropriate, and whether the radar signal angle-of-arrival (AOA) must be computed. The emitter location is computed using a ratio of sequential frequency measurements, and the moving observer continues to collect frequency measurements until the location of the emitter can be established to within a predetermined degree of certainty.

Abstract: A tuned additive mass to a body subjected to forced vibrations that reduces the vibration amplitudes. The mass is coupled to the body in a manner that establishes a node at the previous maximum response of the body to the applied forces. The mass is constructed to respond in a spring like manner so that vibration frequencies of the mass is tunable to provide counter vibrations in the vibration frequency band. Vibration amplitude reduction is establish by vibrations of the mass that are in phase oppositions of the body.

Abstract: A method of manufacturing a flat, composite ("pancake") slip ring is described. An assembly of slip rings of conductive material are formed by photo etching or the like into a plurality of annular, concentric conductive rings, the inner and outer diameters of the rings being connected by alignment tabs. A surface of the rings may be masked prior to plating a precious metal on the opposing surface. The slip ring assembly is aligned with the base and bonded to it prior to removing the alignment tabs.

Abstract: A cover for a fill port of a flow controller of a high pressure fitting for filling a cylinder with a pressurized gas. The cover has a slidable cover plate having elongated flexible members attached thereto, such member having a locking projection that cooperatively fits into a locking recess on the cover plate. The cover plate is movable from a first position covering the fill port to a second position away therefrom. Elastomeric means bias the cover plate towards the first position. A fill port adaptor is used to fill the cylinder through the fill port, and may have a cover that prevents operation when the cover is in place. Both covers are adapted to open when the flow controller is properly placed in a cradle that forms part of the fill port adaptor.

Abstract: A all-plastic ZIF (zero insertion force) electrical connector offers the advantages of low cost and ease of manufacturing inherent to plastic. According to a first embodiment of the invention, an all-plastic ZIF electrical connector has a bias means connected to a first half of the connector for providing a bias force to force the first half of the connector against a PCB (printed circuit board) or other circuitry inserted between the first half and a second half of the connector. According to a second embodiment of the present invention, the all-plastic ZIF electrical connector is attached to a flexible printed circuit which allows a first half of the ZIF electrical connector to be flexed slightly to increase the space between the contact fingers to accommodate insertion of the PCB without the need to force the PCB between the contact-making fingers of the connector when the PCB is inserted into the connector.

Abstract: A gas mixing pressure regulator for a closed circuit breathing apparatus comprises a first inlet to provide pressurized air to the breathing apparatus, a pressure responsive demand valve for opening and closing a first inlet, a second inlet for supplying carbon dioxide-free exhaled air from the breathing apparatus, and a mixing chamber for mixing the pressurized air and exhaled air for supplying breathable air to the breathing apparatus. The demand valve is isolated from the mixing chamber by a check valve injector nozzle to prevent contamination thereof and is responsive to pressure demands from the breathing apparatus to ensure reliability, stability and long life.

Abstract: An electrical surveillance measures system for measuring direction of arrival (DOA), i.e., both azimuth and elevation, of a pulsed or continuous wave radar signal from a moving emitter. Either carrier frequency or pulse repetition interval (PARI) Doppler shift are used whereby the ratio of the Doppler shift is measured by a moving observer. The DOA is measured as a unit vector having basis vectors formed from a linearly independent set of observer's velocity vectors. The DOA unit vector has a linear part where the coefficients of the basis vectors are derived directly from the ratios of frequency or PARI measurements taken in three contiguous dwells. The DOA unit vector has a nonlinear part formed from the requirement that the DOA vector have unit magnitude. The unit vector is resolved in the system coordinates in which emitter azimuth and elevation are defined to allow computation of the latter two values.

Abstract: A direction finding antenna system includes a plurality of monopole elements disposed symmetrically around a center of a circular ground plane at the same radial distance from the center and a multimode combiner connected to the monopole elements to provide one or more mode outputs. A phase difference detector determines phase differences between selected ones of the mode outputs to provide azimuth bearing of a detected object. Typically, four or eight monopole elements are used. Placement of the inherently narrowband monopole elements in a bicone structure having a polarizer grid extends the useful bandwidth. Multiband coverage is achieved with a plurality of such antennas connected by a feed cable positioned on the polarizer grid to avoid interference.

Abstract: A beam sharpened, low sidelobe antenna is obtained by segmenting the antenna to provide two sub-antennas, one of which is arranged as an interferometer. The output signals of the two antennas are added and subtracted to provide sum and difference signals. The sum and difference signals and the output signals are then utilized to provide the desired beam sharpened, low sidelobe antenna.

Abstract: An electrical slip ring base is constructed of flexible and moldable or extrudible material so as to be capable of being formed into a variety of profiles or shapes. A rigid backing or hub stiffens or reinforces the base member. Any form of conductive rings can be used, and the base member can be formed to accommodate them.

Abstract: A slip ring base assembly utilizing a novel construction and manufacturing technique uses a molded or extruded base profile that can be manufactured in various shapes and configurations and is flexible enough to conform to many diameters. A rigid backing is provided, as may be a suitable hub, for stiffening and reinforcing the base profile. Strip or round conducting rings whose surface may be flat, grooved or channeled, are inserted on the base member.

Abstract: Radar emitter carrier frequency or pulse time-of-arrival measurements are used to resolve the differential phase measurement ambiguities on a long baseline interferometer (LBI) used to passively locate the emitter. The LBI requires only two pulses to precisely measure the change in signal angle of arrival caused by observer motion relative to the emitter, whereas frequency Doppler needs tens of pulses, and time Doppler may need hundreds of pulses, to estimate the same change to the same accuracy. Therefore Doppler measurements are made only to the accuracy needed to estimate the angle change accurately enough to differentially resolve the LBI.

Abstract: Method and apparatus for passive emitter location which overcomes the time to range and other restrictive limitations of passive tracking systems by combining pulse frequency, time of arrival and bearing or angle of arrival measurements to obtain a range measurement at each parameter update. No specific observer motion is required and relatively few restrictions on emitter motion are present in order to obtain an accurate determination.

Abstract: A method and apparatus for locating a pulse echo radar emitter in both angle and range using a single antenna and minimal use of the observer platform's navigation instruments are described. The emitter's rest frequency and pulse repetition frequencies are extracted. Using the emitter signal DOA and measurements of pulse TOA and emitter frequency, the observer's acceleration and velocity along the emitter DOA path are found. Combining observer velocity with the above kinematic quantities allows emitter range and bearing to be determined. No observer platform heading or angular attitude information is required.