Abstract: A borehole logging device for obtaining shear wave velocities in formations adjacent the borehole, a device which utilizes a closely controlled, relatively low frequency torsional shear wave. The system includes an elongated housing for suspension within the borehole, said housing including a shear wave source for generating shear waves directly within the borehole wall, and including two spaced, variable reluctance torsional detectors which are also placed in direct contact with the borehole wall. The torsional detectors are, of course, at known spacing from the source such that cross-correlative procsssing of the detector output signals will enable a very accurate phase difference indicative of the shear wave velocity in the formation.

Abstract: 1.

Abstract: The frequency of operation of a tuned flyback type transformer is controlled by a voltage controlled oscillator whose output frequency varies with EHT in such a way that EHT tends to stay constant despite beam current or input voltage variations.

Abstract: A mobile generator for producing waves for seismic exploration. A hammer, mounted on an elongated boom, is dropped to strike an anvil embedded in the ground to create a ground wave. The boom is pivotal between positions selected according to the nature of the wave to be created. A pair of hydraulic piston actuators move the boom between its selected positions. A tensioning device is connected to the cable which drops the hammer in such a manner as to prevent the hammer from rebounding after an impact.

Abstract: A double sideband linear frequency modulation technique for radar applications is disclosed for obtaining simultaneous range and doppler measurements. The method of obtaining measurements is useful in a variety of radar applications; however, the most promising area is in continuous wave radar systems. Linear Frequency Modulated (LFM) waveforms of both increasing and decreasing frequency are simultaneously transmitted. Upon reception, these sideband signals are combined coherently to give an output that is a function of the target's radial velocity. The received signals are also processed separately to obtain target ranging information.

Abstract: An apparatus is described for acoustically investigating a casing in a borehole with a source of acoustic energy that is directed at the reflecting surface of an acoustic reflector in front of which is an acoustically transparent window. The inclination of the window relative to the reflecting surface is selected to deflect secondary transmissions and thus reduce window produced interferences. Several embodiments are described.

Abstract: An antenna beam switching system comprising three antennas whose apertures re disposed in a common plane and which, by means of selective shunting of one or more phase shifters associated with each of the antennas, allows for three dimensional beam switching in at least four directions in space.

Abstract: An acoustic transport member for use in a keyboard having key operated strikers individually actuatable for inducing acoustic energy in the form of sound waves which propagate through the member from selected inducing positions therealong. A first portion of the member is fabricated to provide discrete impact positions for generating sound waves in response to impact actuation of related strikers. A second portion integrally connected with the first portion links all impact positions for receiving and transporting all sound waves generated by the first portion. A step joins the first with the second portions to allow communication of the sound waves from the first portion into the second portion yet thereafter provides unidirectional acoustic separation therebetween which effectively minimizes wave dispersion by substantially isolating the propagating sound waves in the second portion from coming into contact with successive impact positions of the first portion.

Abstract: A seismic streamer cable, composed of a plurality of cable sections includes a common transmission line and an internally mounted inductive element in each section. The inductive elements are coupled in parallel to the common transmission line. A plurality of depth transducers, each associated with an inductive pickup, are secured externally to the streamer cable at desired intervals, adjacent to one of the internal inductive elements. A control signal is periodically transmitted through the transmission line and is received, by inductive coupling, at each transducer after a selected delay. In response to the delayed control signal, the transducers inductively launch a depth-proportional signal into the transmission line for reception by a depth readout device.

Abstract: The present invention relates to a method and apparatus for selectively providing an alarm-generating digital code so as to alert an operator that the next-in-time positions of a source-detector array are the last approved locations before the recording truck location must be changed, i.e., "rolled forward" a predetermined distance along the line of survey and array parameters renormalized.

Abstract: A signal having the form cos (.OMEGA.t+.phi.) where .OMEGA. is the frequency of the signal and .phi. is a phase angle which may be zero is phase shifted to improve the results of the summation of such a signal with other signals having the same form but different phase angles.

Abstract: A spin stabilized, earth orbitting satellite having a phased array antenna capable of radiating a plurality of steered electromagnetic beams to predetermined earth locations. The antenna array extends around the satellite and is made up of individual elements which are energized through semiconductor diode devices by electron beams. The electron beams are controlled by fields having the same frequency as the spin frequency of the satellite.

Abstract: A traffic radar device has a microprocessor controlled system for facilitating the Doppler signal processing. Related circuits enable the Doppler signal to be gathered on a digital basis and arrayed in the memory of the microprocessor unit. The array is then examined and by executing a predetermined algorithm, a decision is made as to whether or not a series of samples of Doppler signals, comprises within the array, represents a valid signal suitable for display as a number indicative of speed of a target vehicle.The microprocessor also controls a tracking filter system over the expected Doppler frequency range and has a duty factor modulation and tunable notch to facilitate the filter operation.The radar device includes a range control that limits the range of the detection of the target vehicle without affecting the detection of the platform vehicle speed.

Abstract: An object location system wherein signals are transmitted or received via more than one transmit station and wherein the objects receive signals from the transmit stations or transmit signals for reception by the treatment stations within a data base region and wherein location coordinates are established in response to the signals received by the transmit stations or in response to the signals received at the object from the transmit stations at a predetermined number of geographic locations within the data base region by positioning the object receiver or transmitter at each of the predetermined geographic locations. The objects are located within the data base region by comparing location coordinates determined in response to signals received at the transmit stations or in response to signals received at the objects with the established location coordinates.

Abstract: An orientation system adapted to be mounted within a vehicle, comprising a display including a rotational heading indicating compass card fabricated from an image retaining fluorescent display panel responsive to bearing data signals generated by selected ones of a plurality of light emitting diodes.

Abstract: A Loran-C receiver cycle detector is disclosed which processes Loran-C signal pulses on a cycle-by-cycle basis of the carrier frequency and generates an output for a specific carrier cycle. Due to received noise, sampling techniques are used to create a histogram which is analyzed to provide feedback used to accurately locate a tracking point on each Loran-C pulse.

Abstract: To eliminate fixed echoes at the receiver of a pulse radar, incoming i-f signals are demodulated, subjected to Doppler filtering, centered and bottom-clipped to eliminate those whose amplitudes lie below a certain threshold. The centering operation and/or the magnitude of the threshold are controlled automatically as a function of the amplitude of the incoming signals as measured upstream of the Doppler filter.

Abstract: The invention is a configuration of digital open-loop cancelers, each of ch uses a batch window sampling technique, for decorrelating a main input signal from a plurality of auxiliary input signals by using one or more iterations of cancellation. The main signal includes a desirable signal and undesirable interference signals. The auxiliary signals include the undesirable interference signals which are correlated with the interference of the main signal. Samples of the main signal and a first auxiliary signal are fed to a first digital canceler. The canceler batches them, (forms the samples in a group) and measures the correlation between the main signal and auxiliary signal. This measurement, or weight, is applied to each of the samples of the auxiliary signal which were used to establish the weight. The weighted auxiliary samples are subtracted from the main input signal to produce an output residue signal that is uncorrelated with the auxiliary signal.

Abstract: Radar tracking or homing units employing three or more primary radiators and utilizing an arrangement of a sum-difference network and signal processing stage to form sum, difference and cross-related or cross-term signals and to effect correction of errors introduced due to the presence or apparent presence of two targets with the resolvable radar volume, using a stipulated method of signal processing.

Abstract: An array of antennas is sequentially sampled by digital commutation means provide a synchronous display of a synthesized antenna array pattern of reception on a cathode ray tube indicator. The commutation means and digital means for generating sine and cosine signals operate from a common oscillator source. Digital means are provided to advance or delay the phase relation of the pattern or of a strobe line with respect to the CRT sweep to effect rotation thereof into azimuthal alignment. Automatic bearing readout is digitally accomplished when alignment is achieved.