Abstract: A Doppler position locator for determining the bearing of a signal source from a moving receiver. The signal source encodes a digital signal indicating its actual transmitting frequency on a transmitted carrier. The moving receiver such as an airplane receives a Doppler shifted carrier frequency and the digital information on what the actual transmitted frequency was. Comparison of the received frequency to the digital information on the transmitted frequency yields a Doppler frequency (the increase or decrease caused by the relative motion, i.e., the numerical difference between the transmitted and received frequencies). From the aircraft velocity and the two frequencies, the bearing can be determined using the formula .crclbar.=cos.sup.-1 (d*c)/(f*v) where .crclbar. is the bearing angle, f is the transmitted frequency, d is the Doppler shift or change in frequency, c is the speed of light and v is the magnitude of the receiver velocity.
Abstract: Method and apparatus for improving the speed and accuracy of processing signals from global positioning system (GPS) receivers by ensuring access to GPS carrier signals that have been modulated with an encrypted P-code sequence. In one disclosed embodiment of the invention, GPS L1 and L2 signals are correlated with a locally generated P-code signal, bandpass filtered to enhance signal-to-noise ratio performance, and then cross-correlated to obtain a signal with an L1-L2 frequency component that facilitates the resolution of carrier cycle ambiguity. In another embodiment, received GPS signals are immediately converted to digital form, then digitally correlated with in-phase and quadrature components of a locally generated P-code signal. Signals resulting from the correlation are then integrated over timing intervals corresponding to a previously determined encryption period to provide in-phase (I) and quadrature (Q) samples.
May 2, 1994
Date of Patent:
July 9, 1996
Magnavox Electronic Systems Company
Charles R. Cahn, Richard G. Keegan, Jerry E. Knight, Thomas A. Stansell, Jr.
Abstract: In a preferred embodiment, an enclosure for an electronic module containing an electronic component having upper and lower surfaces, the enclosure including: a top cover shield overlying, and substantially covering, in closely spaced relationship, the upper surface of the electronic component; a bottom cover shield underlying, and substantially covering, in closely spaced relationship, the lower surface of the electronic component; and the top and bottom cover shields being cojoined so as to substantially enclose the electronic component.
Abstract: In a preferred embodiment, an environmentally insensitive electric detonator system for demolition, including: an object to be demolished; a main explosive charge in proximity to the object to be demolished; electrically activated detonator apparatus including a relatively insensitive initiating charge in proximity to the main explosive charge; and circuitry having input apparatus to receive an input firing pulse and having output apparatus to provide, through arbitrarily long wires, a high voltage in response thereto across the electrically activated detonator apparatus to cause ignition of the main explosive charge.
April 22, 1994
Date of Patent:
February 6, 1996
Paul C. Gilpin, Magnavox Electronic Systems Company
Abstract: A technique for smoothing pseudorange code measurements made in a global positioning system (GPS) receiver, with carrier phase measurements, over an extended time interval but without distortion that usually results from a divergence between code-derived pseudorange measurements and carrier-derived measurements. The basic principle of the invention is to remove ionospheric effects and Doppler effects from the pseudorange code measurements prior to filtering over an extended time interval. Removal of ionospheric effects may be effected by applying corrections received from a reference receiver, or may be accomplished using measured or modeled ionospheric data available to the receiver. The invention is applicable to differential GPS position finding using remote receivers having only a single-frequency capability, but is also applicable to stand-alone GPS receivers of any type.
Abstract: In a preferred embodiment, a slapper detonator, including: an inverted, vertical, open cup filled with an explosive, the mouth of the cup being adjacent the upper surface of a horizontally disposed explosive foil initiator (EFI); an integral flange extending circumferentially horizontally outwardly around the mouth of the cup; a cover plate having an opening defined therethrough and attached to the upper surface of the EFI, through which opening the cup extends vertically; and a counterbore defined around the perimeter of the opening to engage the flange and hold the mouth against the upper surface, such that lateral forces applied to the cup will be transferred to the cover plate. In another aspect of the invention, there is provided an EFI for a slapper detonator which has solderable electrical terminals. The EFI may be of laminated structure with the terminals laminated to the structure. In a further aspect of the invention, there is provided an improved barrel structure for an EFI.
Abstract: A method of and apparatus for transmitting or receiving circularly polarized signals is disclosed. The technique employs a phase shifting network for connection between an antenna and a radio transmitter or receiver to produce a phase shift when transmitting or eliminate a phase shift when receiving. In one preferred embodiment, a dielectric substrate has a phase shifting network or printed circuit lines defining a signal transmission paths between a radio connection terminal and a plurality of antenna element connection terminals for coupling a multi-element antenna and a radio. Each transmission path is phase shifted relative to an adjacent path by a predetermined amount by each path having progressively equally different electrical length to provide equal phase shift of a radio frequency signal progressively through the transmission paths.
Abstract: In a preferred embodiment, an optical rotation sensor for a rotating member, the optical rotation sensor including: at least one reflective element disposed on the surface of the rotating member; first light transmission means to transmit light from a light source, disposed at the proximal end of the first light transmission means remote from the rotating member, to illuminate the surface of the rotating member at the distal end of the first light transmission means; and second light transmission means to transmit from the distal end of the second light transmission means to a first photodetector, disposed at the proximal end of the second light transmission means remote from the rotating member, light reflected from the at least one reflective element as the at least one reflective element passes the distal end of the second light transmission means as the rotating member rotates.
Abstract: A system for processing modulated signals received, together with at least one interference signal, by an array of antenna elements in a communications receiver. The method of the invention includes demodulating the received signals, and processing the demodulated signals to produce an output signal that is substantially free of any interference signals, while at the same time effectively steering the antenna pattern produced by the array of elements, to move any spurious nulls in the pattern away from a source of information signals. This results in avoidance of any cycle slipping problems that might otherwise arise in receiver tracking control loops, and has the added benefit of significantly improving performance as measured by the signal-to-noise ratio.
Abstract: In a preferred embodiment, an accelerometer sensor system, including: a housing structure; a first acceleration sensor disposed in the housing structure at a first selected location along the vertical axis of the housing structure, the first acceleration sensor providing a first output; a second acceleration sensor disposed in the housing structure at a second selected location along the vertical axis, the second acceleration sensor providing a second output; and apparatus to combine the first and second outputs of the first and second acceleration sensors such as to simulate the output from a virtual acceleration sensor located at any selected location on the vertical axis, allowing one to reduce noise induced by pitch motion, at any desired frequency or across a desired frequency band.
Abstract: In a preferred embodiment, a battery including a plurality of series connected battery cells rolled into a cylindrical form. Each of the battery cells includes a thin flexible rectangular anode closely spaced apart from a thin flexible cathode. The plurality of series connected battery cells are placed on a flexible carrier sheet which is tightly wound into the cylindrical form.
Abstract: In a preferred embodiment, a gas generator system for providing underwater buoyancy, including: a housing for the placement therein of a solid chemical to produce a gas upon reaction of the chemical with water; an inlet in the housing to bring the water in contact with the chemical; a float attached to an upper portion of the housing to receive the gas and thereby to become inflated so as to effect the buoyancy; a pressure plate to continually bear against the upper surface of the chemical as the chemical is consumed by the reaction, the pressure plate having defined therethrough a plurality of apertures, the total area of the apertures being selected so as to control the rate of reaction of the chemical and being spaced so as to permit even distribution of water to the surface of the chemical; and a biaser to cause the pressure plate to continually bear against the upper surface of the chemical as the chemical is consumed.
Abstract: In a preferred embodiment, there is provided a compact rotatable electrical device for attachment to a mounting panel of an electrical apparatus. The mounting panel has inner and outer surfaces and defines an interior space of the apparatus, with the inner surface adjacent the interior space. The device includes: a control body having a control shaft extending upwardly from the distal end thereof, the proximal end of the control shaft being connected to operative elements within the control body; and apparatus for attachment of the proximal end of the control body to the mounting panel through an opening defined therethrough such that the control body, when so attached, will be disposed substantially outside the interior space.
Abstract: In a preferred embodiment, an accelerometer sensor system, having a first axis of rotation at a first given frequency of periodic oscillation thereabout, which accelerometer sensor includes: a first acceleration sensor; a platform to which the first acceleration sensor is fixedly attached; and the first acceleration sensor being vertically displaced from the first axis of rotation by a first selected distance such that the noise received by the first acceleration sensor, due to the periodic oscillation at the first frequency, is reduced.
Abstract: In a preferred embodiment, a method for excising narrow band interferers in a spread spectrum signal communication which includes the steps of: receiving the spread spectrum signal; digitizing the spread spectrum signal; transforming the digitized signal from the time domain to the frequency domain; discarding the magnitude of the digitized signal and replacing it with a normalized value; and transforming the digitized signal back to the time domain.
Abstract: A pseudo-noise (PN) correlation and demodulation method and apparatus, in which received signals are correlated with locally generated PN codes and correlation measurements are maintained for multiple time bins corresponding to signals received over possible multiple paths. Instead of selecting one or a small number of significant correlation measurements to control data demodulation, the method of the invention performs data demodulation over the multiple time bins, and then selects data values corresponding to significant correlation measurements and combines the selected data values, weighting them in accordance with their relative strengths a determined during correlation. Use of the invention provides improved performance in terms of signal quality and continuity in the presence of multipath conditions. Careful selection of design parameters allows the improved performance to be obtained in a compact and easily portable implementation including transmitter and receiver modules.
Abstract: An improved solid state spark gap for use, for example, in firing munitions. The spark gap is formed by depositing a trigger electrode on a dielectric substrate, precisely covering the trigger electrode and an adjoining area with a dielectric layer, and forming an anode and a cathode on the dielectric layer with a spark gap there between. The anode and cathode do not overlap the trigger electrode. The spark gap may be enclosed within a hermetically sealed inert gas filled cover.
January 24, 1990
Date of Patent:
June 1, 1993
Magnavox Government and Industrial Electronics Company
Chiman R. Patel, Timothy B. Bonbrake, Barry L. Driscoll
Abstract: In a preferred embodiment, a tab-fuse for connecting two adjacent cells in a multicell battery, which includes: a metallic member having a base portion for attachment to the positive end of one of the adjacent cells and a tab portion which is bendable for attachment of the distal end thereof to the negative end of the other of the adjacent cells; and the base portion and the proximal end of the tab portion being joined by a relatively narrow portion of selected width, such that the narrow portion serves as a fusible link for overcurrent protection.
May 21, 1992
Date of Patent:
April 20, 1993
Magnavox Electronic Systems Company
Ted J. Miller, Dean P. Stanley, Kent A. Snyder
Abstract: In a preferred embodiment, inlet and outlet manifolds for a forced electrolyte flow battery, the manifolds having nonuniform cross-sections. The inlet manifold extends along the base of the battery cells and tapers from a large cross-section at the inlet end thereof to a small cross-section at the closed opposite end of the manifold. The outlet manifold has electrolyte outlets at either end of the manifold and tapers from a small cross-section at the middle of the manifold to large cross-sections at the electrolyte outlets of the manifolds. The inlet and outlets to and from the inlet and outlet manifolds are arranged, respectively, such that the header connected to the inlet manifold is larger in cross-section than the cross-section of the inlet manifold at that point and the headers connected to the outlet manifold are larger in cross-section than the cross-sections of the outlet manifold at that point.
Abstract: A technique using pseudo-satellites, or "pseudolites," for resolving whole-cycle ambiguity that is inherent in phase-angle measurments of signals received from multiple satellite-based transmitters in a global positioning system. The relative position of a secondary receiving antenna with respect to a reference antenna is approximately known or approximately initially determined and then measurements from a minimum number of satellites are used to determine an initial set of potential solutions to the relative position of the secondary antenna that fall within a region of uncertainty surrounding the approximate position. Redundant measurements are taken from one or more pseudolites, and used to progressively reduce the number of potential solutions to close to one.