Abstract: A current transducer for rugged environments uses a solid permalloy core including a magnetic gap for a Hall effect generator and rigid mounting extensions.

Abstract: A power connect safety and connection interlock system is shown for use with inverters and other DC loads (16) which include capacitor filter banks (14) at their DC inputs. A safety circuit (20) operates a spring (26) biased, solenoid (22) driven mechanical connection interference (24) which prevents mating and therefore electrical connection between the power contactor halves (11, 13) of the main power contacts (12) until the capacitor bank is safely precharged through auxiliary contacts (18). When the DC load (16) is shut down, the capacitor bank (14) is automatically discharged through a discharging power resistor (66) by a MOSFET transistor (60) through a discharging power resistor (66) only when both the main power contacts and auxiliary contacts are disconnected.

Abstract: Capacitive device to measure changes in liquids, such as changes in the mixing ratio of composite liquids, utilizing capacity measured by an electrode probe. An isolating body is located between the electrodes in the liquid and causes a deviation of the field lines to lower the field strength on the electrodes to avoid measurement disturbances from dirt and air bubbles or other contaminants. Furthermore, circuitry for measuring the capacity independently of any disturbing effects of variable ion concentration in the liquid. This is carried out by separately evaluating the phase of a high-frequency signal on a resonance circuit connected to the electrodes.

Abstract: A device for taking trousers off a double-leg ironing machine having an ironing board receiving the trouser legs in spread position, a gripper mounted for motion along the ironing board including two clamping plates arranged in the transverse direction of the ironing board at least one of which is mounted for vertical motion and can be lowered to the surface of the ironing board. The gripper grips, raises and transports one trouser leg along the longitudinal axis of the board and releases it at the end of the other trouser leg. This positions the ends of the trouser legs together so that they can be gripped manually or mechanically and held by a clamping hanger for further transport. A transport system is provided.

Abstract: A controllable semiconductor laser system including a plurality of semiconductor regions operated at unequal saturation photon densities to permit optical and/or electrical control of lasing in at least one resonant cavity formed therebetween. A pair of such regions may operate as a controllable laser at greater than 100% differential quantum efficiency.

Abstract: A semiconductor laser diode in which oblate-spheroidal modes are established to enhance emitted beam characteristics. The laser diode laser cavity ends are configured in the shape of Fresnel lenses.

Abstract: A technique for the non-intrusive position determination of one or more natural or artificial acoustic transmitters (S1, S2, S3) in marine or terrestrial environments by processing data from five or more receivers (R1, R2, R3, R4, R5) distributed in the area. The data processing includes cross correlation (24) of receiver data to determine differences in acoustic data travel times (MTTD) and tomographic reconstruction (16) to determine transmitter position as well as receiver position (42), wind or current (40) and sound speed or temperature fields (44) and errors (41) associated with all of the above. Accuracy can be greatly enhanced by use of calibration transmissions at receiver or other known or unknown position locations. Position and wind, sound speed and error fields may conveniently be displayed by computer generated maps (18, 20, 22, 43).

Abstract: A modified laser tube including a second pinch off tube or port for flowing argon and krypton gas through the laser for processing to remove contaminants to improve performance of new and used tubes such as ALC 60X argon ion lasers. Lasing discharge is maintained during processing to release contaminants for removal by plasma scrubbing of the laser bore. A magnetic field is applied and rotated in a plane perpendicular to the laser during discharge to enhance contamination release during plasma scrubbing. Preliminary cathode activation, control of gas flow rates and tube power as well as alternating of argon and krypton gas controls the contaminant release rate to prevent recontamination of the laser by released contaminants before removal.

Abstract: Method and apparatus are disclosed for accurately determining position from GPS satellites and received on a ship using C/A code group delay observable TAU, 308 f.sub.o implicit carrier phase observable PHI, L1 band implicit f.sub.o carrier residual phase observable PSI.sub.L1, and L2 band implicit f.sub.o carrier residual phase observable PSI.sub.L2. A precise measurement of the group-phase delay range to each satellite is made based upon the L1 center frequency carrier phase. A correction for ionospheric effects is determined by simultaneous observation of the group delays of the wide bandwidth P code modulations in both the L1 and L2 bands. These group delays are determined by measuring the phases of carrier waves implicit in the spread-spectrum signals received in both bands. These carriers are reconstructed from both the L1 and L2 band signals from each satellite without using knowledge of the P code.

Abstract: A method and a system are disclosed for measuring the baseline vector b between a pair of survey marks on the ground by radio interferometry using radio signals broadcast from the earth orbiting satellites of the NAVSTAR Global Positioning System (GPS), the radio signals broadcast by the satellites being double-sideband modulated with their carriers suppressed. An antenna is positioned at each survey mark. The signals received by one antenna during a predetermined time span are separated into upper and lower sideband components. These separate components are filtered, converted to digital form, and then multiplied together. Their product is analyzed digitally by means of correlation with quadrature outputs of a local oscillator to determine the power, and the phase relative to that local oscillator, of the carrier wave that is implicit in the double-sideband signal being received from each satellite. Differences in Doppler shift are utilized to distinguish the carriers of different satellites.

Abstract: System and method are disclosed for determining position related data from spread spectrum signals using reconstructed carrier receivers with continuous wave interference rejection. The spread spectrum signals are collected at a mark with a substantially omni-directional antenna and continuous wave interference is then rejected at or near a selected frequency. The spread spectrum signals are then reconstructed to provide a continuous wave component at that frequency form which the position data may be derived. The data is derived without interference because the potentially interfering signals, if present, have been rejected before the components were reconstructed.

Abstract: An ultrasonic circulating air brush scrubber with a supply of scrubbing liquid in finely dispersed form in the intake air stream, and a high-voltage ionizer, includes at least one circular brush downstream of the ionizer. The brush is driven at high speed and is at the opposite potential from the ionized air stream. The circulating air scrubber provides a high degree of cleaning action for particle sizes down to below 1 .mu.m., low consumption of scrubbing liquid and dries the air on the output side.

Abstract: Method and apparatus are disclosed for accurately determining position from GPS satellites and received on a ship using observations of C/A code group delay, L1 band center frequency carrier phase, L1 band 5.115 MHz implicit carrier phase, and L2 band 5.115 MHz implicit carrier phase. A precise measurement of the range to each satellite is made based upon the L1 center frequency carrier phase. A correction for ionospheric effects is determined by simultaneous observation of the group delays of the wide bandwidth P code modulations in both the L1 and L2 bands. These group delays are determined by measuring the phases of carrier waves implicit in the spread-spectrum signals received in both bands. These carriers are reconstructed from both the L1 and L2 band signals from each satellite without using knowledge of the P code. The unknown biases in the L1 center frequency carrier phase range measurements are determined from simultaneous, pseudorange measurements, with time averaging.

Abstract: A low power, differential ECL line driver has a switching network that applies a constant current source as the emitter load to only one of the output transistors at a time while applying a constant current source to the base of the other output transistor.

Abstract: An acoustic travel time flow meter, for use in measuring turbulent vector flow data, capable of extended deployment in which acoustic pulse generation and measurement are interleaved to conserve battery power and compressed data, sufficient to reconstruct turbulent flow data, are derived from instantaneous measurements to conserve data storage. Transmitter output and receiver input impedances are matched to reduce instrument error.

Abstract: Method and apparatus for making depth related measurements from an untethered, gravity driven oceanographic platform. The platform is a smooth streamlined, torpedo shaped body releasably carrying ballast in its nose and covered with syntactic foam for buoyancy. At the appropriate depth, the ballast is released and the body ascends under control of an interferometric homing system which guides it to a recovery vessel. The ballast may be an iron slug held in place electromagnetically.

Abstract: A method and a system are disclosed for measuring the baseline vector b between a pair of survey marks on the ground by radio interferometry using radio signals broadcast from the earth orbiting satellites of the NAVSTAR Global Positioning System (GPS), the radio signals broadcast by the satellites being double-sideband modulated with their carriers suppressed. An antenna is positioned at each survey mark. The signals received by one antenna during a predetermined time span are separated into upper and lower sideband components. These separate components are filtered, converted to digital form, and then multiplied together. Their product is analyzed digitally by means of correlation with quadrature outputs of a local oscillator to determine the power, and the phase relative to that local oscillator, of the carrier wave that is implicit in the double-sideband signal being received from each satellite. Differences in Doppler shift are utilized to distinguish the carriers of different satellites.

Abstract: A circularly polarized microwave radio antenna which is constructed so that its phase center can be very easily and very accurately positioned with respect to a marker point over which the antenna is placed is disclosed. The antenna includes a ground plane, antenna elements in a common plane parallel thereto and supported by a perpendicular center post, separate feed lines for each element and a combining network all positioned symmetrically about an axial bore in the center post so that the phase center of the antenna is on the axis of the center post at the intersection with the upper surface of the ground plane. A graduated rod may be positioned in the bore to align the antenna with the marker point.

Abstract: Sweeps of seismic signals consisting of pulse trains having a predetermined number of pulses in which the periods or durations of the pulses are randomized and in which the wave shape and relative time displacements of the pulses in different trains provides substantially constant spectral level over a frequency range containing several octaves even though the durations of the pulses correspond to a frequency range not exceeding an octave during the sweep are transmitted through the medium being explored such as an earth formation to receptors such as geophones or hydrophones. Groups of signals contained in less than the entire length of the sweep which are transmitted and which are received can be cross correlated to vary the effective duration of the sweep. The cross correlation output of successively occurring sweeps may be stacked to reduce the side lobe amplitude of the cross correlation outputs from each sweep, from which outputs seismograms may be constructed.

Abstract: The seismic method comprises in one preferred embodiment, towing a long, flexible member over the earth's surface, the member having liquid-filled geophones mounted thereon or coupled thereto and suitably spaced therealong, and a seismic cable for receiving the individual outputs of the geophones. Each liquid-filled geophone provides an output electric signal having a polarity corresponding to the direction of the earth's motion. In another embodiment of the method of this invention, the geophones are positioned on the earth's surface in a predetermined pattern; their output signals are transmitted to a utilization device; then the geophones are moved to another location, and the detection process is repeated.In a simplified embodiment, the geophone comprises a hollow cylindrical casing defining a chamber therein. A high-density liquid substantially fills the chamber. The chamber has a flexible bottom wall which constitutes a force or pressure transducer.