Abstract: A fastener assembly is shown including a cylindrical support structure with a bore provided partially therein, the bore having a wall surface with a slot, and a bushing, disposed within the bore of the cylindrical support structure, having an end and an outer surface with a slot therein. The bushing further includes a bore with a first portion having a first diameter and a second portion having a second different diameter, the bushing also having a pair of tangs extending from the end. The fastener assembly further includes a nut, partially disposed within the second portion of the bore of the bushing, the nut having an outer surface with a pair of lugs disposed on the outer surface to engage the pair of tangs of the bushing and a pin disposed juxtapositional the slot of the wall surface of the cylindrical support structure and juxtapositional the slot of the bushing.

Abstract: A system for providing advance warning of underwater navigation hazards that threaten safe ship passage is provided. The system includes a sonar transmitter/receiver adapted for mounting on the ship in a forward looking direction. A processor, in response to sonar returns produced by the sonar transmitter/receiver, produces a sonar produced slope profile of a region of the sea bottom in front of the path of the vessel. A memory stores a slope profile of the region of the sea bottom in front of the vessel, such profile being developed from charted depth data. The stored charted depth data developed slope profile is compared with the sonar return produced slope profile to determine whether the sonar produced slope profile and the charted depth data slope profile are consistent with each other.

Abstract: A method of processing IR signals from a repetitively scanned array of photovoltaic cells is shown to consist of the steps of: (a) subtracting IR signals received on successive scans to produce response signals corresponding only to IR signals from moving or scintillating objects; (b) generating inhibiting signals for IR signals from the edges of wind-driven clouds or from scintillating objects; and (c) inhibiting those response signals that are from the edges of moving clouds or scintillating objects.

Abstract: An elastomer support for a sonar transducer includes a ceramic stack electromechanical driver, a pair of rigid support members, and a pair of elastomer layers disposed between the ceramic stack electromechanical driver and the support members. The elastomer support provides effective mechanical stress reduction in the ceramic stack driver, as well as, a simple, reliable heat dissipation means for the transducer.

Abstract: An apparatus for processing a stream of digital data to provide a set of linear prediction coefficients and prediction error sequence representing said block of data which, when used to reconstruct the block of data, will reconstruct the data with a minimum distortion level is described.

Abstract: A target tracking radar receiver for use in a semiactive tracking system wherein elevation angle data, azimuth angle data and Doppler frequency shift data are processed in a manner which enables narrow band filtering of target angle tracking data in the first intermediate frequency stage. The receiver is arranged to track, simultaneously, variations of target Doppler frequency and of transmitter frequency to permit the desired early narrow band filtering of the received angle data.

Abstract: A radio frequency circuit includes a first RF switch having a first common port coupled to an input port of the switch circuit and a first pair of branch ports and a second RF switch having a second common port coupled to an output port of the circuit and a second pair of branch ports. The radio frequency circuit further includes an RF propagation network having a first end coupled to a first one of said first pair of branch ports of said first RF switch and a second end coupled to a first one of said second pair of branch ports of said second RF switch. The radio frequency circuit further includes an RF termination having an impedance characteristic corresponding to an impedance characteristic of said first common port and having a first end coupled to a second one of said first pair of branch ports of said first RF switch and a second end coupled to a first reference potential.

Abstract: A combined infrared-radar detection system wherein a radar antenna also serves as the primary mirror in an infrared focusing arrangement.

Abstract: A flexural transducer includes a hollow tube that is magnetically driven by a coil/magnet assembly. A magnetic field is provided by passing a current through the coil. The filed passes through an air gap between the coil and the magnet to attract and repel the magnet during alternating portions of the current's cycle. The magnetic transducer driver mechanism permits high drive capability, high temperature operation and provides lower frequency operation than conventional ceramic drivers.

Abstract: A target tracking radar receiver for use in a semiactive tracking system wherein elevation angle data, azimuth angle data and Doppler frequency shift data are processed in a manner which enables narrow band filtering of target angle tracking data in the first intermediate frequency stage. The receiver is arranged to track, simultaneously, variations of target Doppler frequency and of transmitter frequency to permit the desired early narrow band filtering of the received angle data.

Abstract: A calibration circuit includes a plurality of signal sources each of said signal sources having an output port and providing a signal having a known phase and a signal combiner circuit having a plurality of input ports and an output port with each of said input ports being coupled to a corresponding one of said signal source output ports. The calibration circuit further includes a switch having a common port and at least one branch port, said branch port being coupled to said output port of said signal combiner circuit and an analog to digital converter circuit having an input port coupled to the common port and an output port. The calibration circuit further includes a central processing unit coupled to the output port of said analog to digital converter and a summing circuit having a first input port coupled to said central processing unit, a second input port coupled to the output port of said analog to digital converter circuit and an output port.

Abstract: A compliant cover for use with acoustic source transducers includes a rubber boot bonded to a shell of the transducer. The cover has a groove molded within a surface thereof to allow the shell to expand and contract with reduced resistance. Conventional transducers having rigidly mounted covers disposed on the shell which resist the motion of the shell and decrease the overall efficiency of the transducer.

Abstract: A voltage regulator is provided for producing a predetermined output voltage level. The voltage regulator has a voltage source for providing a plurality of successively increasing voltage levels at a corresponding plurality of output terminals, or taps. A controller is provided for automatically selecting, in response to an electrical control signal, the one of the taps providing a voltage level above the predetermined output voltage level. In a preferred embodiment of the invention, the selected tap is the one of the plurality of taps producing a voltage level closest to, and greater than, the predetermined output voltage level. With such an arrangement, the electronic control signal allows a convenient way to select an output voltage level closest to, and greater in magnitude than, the predetermined voltage level, thereby improving the efficiency of the regulator.

Abstract: A ball bearing assembly with a spacer to prevent ball bearing failures. The spacer has a ring with a tongue that fits into a groove in a second spacer ring. One spacer ring is coupled to the outer ring of the ball bearing assembly and the other spacer ring is coupled to the inner ring of the ball bearing assembly. The spacer therefore allows relative rotation of the rings of the ball bearing assembly but prevents relative translation of the rings beyond a point which will damage the ball bearing assembly.

Abstract: An improved sonar signal processor and display combining the use of both coherent and incoherent signal processors. In addition to a conventionally used matched filter detection processor, an incoherent signal processor comprising a cross-range energy filter and a down-range energy filter is used. The cross-range energy filter detects objects characterized by a narrow bearing response; whereas the down-range energy filter detects objects characterized by a narrow range response. The detection events resulting from the incoherent signal processor are displayed in a subdued color to prevent distraction from the primary display events and to reduce the false alarm rate by allowing the sonar operator to view events in the context of natural boundaries.

Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic countermeasures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome on a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radomeinduced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.

Abstract: An improved local oscillator arrangement for a monopulse receiver in a semiactive missile guidance system is shown. The monopulse receiver includes an improved reference local oscillator wherein a first local oscillator signal and a pair of reference signals required to demodulate the output of the intermediate frequency section of such receiver are derived simultaneously from the output of a single voltage controlled crystal oscillator. The frequencies of the first local oscillator and the pair of reference signals are related to the frequency of the radar modified by any Doppler shift frequency experienced during an intercept.

Abstract: A bar code wand reader adapted to read a bar code disposed on a narrow surface such as an edge of a printed wiring board is shown to include a bar code wand reader adapter (32) affixed to an end of a bar code wand reader (34). The adapter includes a fore surface having a slot (30) provided therein. The slot is adapted to hold the bar code wand reader at a constant distance and position from the edge of the narrow surface having the bar code disposed thereon. With such an arrangement, the bar code reader is held at a proper disposition as the bar code wand reader is passed over the bar code disposed on the narrow surface. The latter provides a proper reading with a single passing and prevents the necessity of numerous attempts at reading the bar code.

Abstract: A composite split cylinder transducer comprises an electromechanical driver and a cylindrical shell having a longitudinal gap. The shell further has a portion, disposed opposite the gap, comprised of a high strength material having increased stiffness. Transducers of this configuration are capable of being employed at greater ocean depths where high hydrostatic pressure conditions exist with little effect on acoustic performance.

Abstract: An AWTSS is shown to be made up of an improved synthetic aperture radar (SAR) for generating radar maps with various degrees of resolution required for navigation of an aircraft and detection of ground targets in the presence of electronic countermeasures and clutter. The SAR consists, in effect, of four frequency-agile radars sharing quadrants of a single array antenna mounted within a radome on a "four axis" gimbal with a sidelobe cancelling subarray mounted at the phase center of each quadrant. Motion sensors are also mounted on the single array antenna to provide signals for compensating for vibration and stored compensating signals are used to compensate for radome-induced errors. In addition, a signal processor is shown which is selectively operable to generate radar maps of any one of a number of desired degrees of resolution, such processor being adapted to operate in the presence of clutter or jamming signals.