Abstract: A device providing summarized information from the digital spectrum analyzer output within a Doppler radar. Four memories, each of 256 word capacity, are included. Each of said memories is addressed by a group of eight bits among the sixteen bits provided by the spectrum analyzer and a logic circuit reconstitutes an elementary summary plot from the contents of said four memories. For a sixteen-line spectrum analyzer it is thus possible to replace a read-only memory for 64K, seven-bit words by the aforementioned four such read-only memories each of 256, seven-bit words.

Abstract: A range processor for airborne distance measuring equipment in which coherency of reply signals from the ground based DME station is determined by incrementing the contents of storage locations of a random access memory device for each reply signal according to the time of reception of the reply signal and for decrementing the contents of the storage location if no reply signal is received. Whenever the contents of a storage location exceeds a threshold value a range gate is generated so that the next reply received within the range gate causes the time of reception of the reply to be stored as range data.

Abstract: Seismic pulse waveforms are generated for travel through subsurface formations. Both normally-reflected and obliquely-reflected waveforms from subsurface interfaces are recorded. The differential phase change between the normally-reflected and obliquely-reflected waveforms are determined for each interface. The fluid characteristics of the porous subsurface layers are identified as gas-saturated or water-saturated in response to the relative amounts of phase change, a gas-saturated layer providing a larger phase change than a water-saturated phase change.

Abstract: The invention relates to Doppler radar making it possible to subject the ground to surveillance.It consists of providing a conventional Doppler radar having a transmitter, a receiver, processing means making it possible to supply a binary signal indicating the presence or absence of a moving target in the given distance gate series and a display screen with means making it possible to take account of certain relative danger criteria, as a function of the distance at which the targets are located and as a function of the speed at which they are moving. These means make it possible to control the screen, in order that the relative danger is displayed in the form of an overbrightness for the targets considered dangerous.It makes it possible to improve the display conditions of ground surveillance Doppler radars.

Abstract: A logging instrument is caused to traverse a cased earth borehole periodically emitting and receiving acoustic energies, such instrument generating an electrical signal containing one or more electrical alternations representative of the received acoustic energies, and such alternations having an amplitude generally functionally related to the attentuation of the acoustic energies as they traverse the casing within the borehole. A significant portion of these alternations is determined and digitized, and the individual digitized values therein summed together to yield a functional representation of the signal area of the alternations of a predetermined polarity within the significant portion. This signal area is then compared to the area which would be indicated if the casing were free of cement bonding, the comparison yielding an indication of the relative degree of bonding of cement to the casing within the borehole.

Abstract: By using two SAR antennas spaced a known distance, B, and oriented at substantially the same look angle to illuminate the same target area, pixel data from the two antennas may be compared in phase to determine a difference .DELTA..phi. from which a slant angle .theta. is determined for each pixel point from an equation .DELTA..phi.=(2.pi.B/.lambda.)sin(.theta.-.alpha.), where .lambda. is the radar wavelength and .alpha. is the roll angle of the aircraft. The height, h, of each pixel point from the aircraft is determined from the equation h=R cos .theta., and from the known altitude, a, of the aircraft above sea level, the altitude (elevation), a', of each point is determined from the difference a-h. This elevation data may be displayed with the SAR image by, for example, quantizing the elevation at increments of 100 feet starting at sea level, and color coding pixels of the same quantized elevation.

Abstract: In a target detection communication system, apparatus and method for determining the presence of probable targets based on contacts (which can indicate the presence of a target, noise, chatter, or objects not of interest) detected within a predefined position sector or sectors over a specified number of scans. The position of each detected contact, as a contact of interest, is compared with the positions of contacts detected at previous times or scans. Velocity profiles indicate which previous contacts support the likelihood that the contact of interest represents a target having a velocity within a defined band. The likelihood, which can be represented by a quality value, may be a function of number of contacts, timing of contacts, or both the number and timing of contacts in a given velocity profile. A preselected threshold value, which is related to false alarm rate, is compared to the most likely, or highest quality, velocity profile associated with a contact of interest.

Abstract: An optical communication system for drill hole logging comprises an armored cable containing one or more glass clad optical fibers inside a tubular moisture barrier, a neodymium laser in the cable reel radiates infrared light into one of the fibers, a modulator in the downhole cable-head connector shell modulates light and returns it to the surface, and a semiconductor detector in the reel demodulates the data signal from the returning light.

Abstract: A method and apparatus for determining the position of a vessel in distress and transmitting an auditory distress message containing the position of the vessel. The apparatus obtains the position of the vessel as determined by a LORAN-C type receiver from either a cassette or directly from the LORAN-C receiver and generates a "Mayday" message including the identification of a vessel, the position of the vessel and the nature of the emergency. The "Mayday" message is synthesized into an auditory human or Morse code message. The language of the auditory message is preferably chosen to correspond with the most likely language used by a possible receiver of the "Mayday" message. Also preferably, the apparatus determines whether the primary distress radio frequency is clear; should the primary distress frequency be in use, the apparatus automatically shifts to a secondary frequency and transmits the "Mayday" message.

Abstract: A modular telemetry cable system having first and second array terminals spaced apart a distance of D. A cable extends between the terminals having X number of analog signal transmission means which is connected to 2X transducer sets for gathering 2X analog signals. The analog signals are processed and transmitted as digital signals over a digital transmission means connected between the terminals. At the location in the cable of the two interior transducer sets, the cable is penetrated to connect the interior transducer sets to the same analog transmission means. The portion of the same analog transmissions means between the two interior sets is disconnected from the two interior sets. At the penetrations in the cable of the two interior sets, the other analog transmission means are cut. One transducer set on opposite sides of the cuts in the other transmission means are connected to each of the other analog transmission means.

Abstract: Apparatus for shear wave logging of formations adjacent a borehole wherein a tubular apparatus is specifically constructed for sympathetic movement with the borehole in response to low frequency horizontal shear waves. The apparatus consists of tubular frame structure with end members including housings for rigid seating of orthogonal pairs of horizontal wave detectors. Outer sleeve structure may be utilized for buoyancy adjustment.

Abstract: A borehole logging tool employs an energy transmitter and receiver for scanning a borehole with energy pulses. An orientation pulse is produced each time the tool rotates past a predetermined orientation position. The time period between orientation pulses is measured and divided into a plurality of discrete intervals. Sine and cosine functions are generated for the measured time period having a sine and cosine value corresponding to each of the discrete intervals. The sine and cosine functions are used to produce sweep functions for controlling the outward sweep of the electron beam of a PPI display device so as to produce a circular rotating pattern in which each revolution corresponds in time to a measured time between orientation pulses. The output of the receiver modulates the electron beam sweep to generate a visual display of the azimuthal scan of the borehole.

Abstract: An intrusion detection apparatus utilizing a plurality of bistatic pulse-overlap Doppler radar units to detect target Doppler frequency shifts in an enclosed sensitive volume and utilizing a single RF frequency with different pulse repetition rates to synchronize the bistatic receiver unit with its associated transmitter unit.

Abstract: A borehole logging system includes a borehole logging tool, a logging tool depth encoder for indicating rate of movement of the logging tool, a moving recording medium, and a recording encoder for indicating the actual rate of movement of the recording medium. The logging rate indicated by the depth encoder is used to provide a signal representative of a desired recording rate. This desired recording rate is compared to the actual recording rate and correction made to the recording rate when there is a variance between such desired and actual recording rates.

Abstract: In distance measuring equipment apparatus which includes an antenna; a transmitter/receiver coupled to the antenna to transmit interrogation pulses and receive responses from a ground station, the pulses being spaced apart, the ground station also transmitting other responses between the responses; and a data processor receiving video and gate signals from the transmitter/receiver and calculating therefrom the distance to the ground station in order to calibrate for receiver and installation delays. The receiving signal, other than when one of the responses is being received, is modulated. The phase of the resulting modulation on the video signal with respect to the phase of modulation at the modulator is detected to determine the receiver and installation delay.

Abstract: An improved siren including means for producing and directing sound energy against a rotatable reflector which directs the sound waves out from the siren in a generally horizontal direction and which due to rotation of the reflector about a vertical axis causes such sound waves to be directed in all horizontal directions. One embodiment includes rotor and stator means which create sound energy that is directed generally downwardly in the manner of a ring radiator, together with a reflector mounted beneath the rotor and stator for rotation about a generally vertical axis, the reflector being tilted relative to its axis of rotation to intercept the downwardly directed sound waves and direct them out horizontally thereby providing a directional siren which covers a 360 degree area due to rotation of the reflector.

Abstract: A pulse Doppler radar receiver which continuously monitors successively obtained amplitude values Ao through An with the disrupted amplitude values which deviate by a prescribed value from an interpolation value obtained from adjacent undisturbed amplitude values are determined and are limited to a value obtained from the interpolation value or from the largest or smallest adjacent undisrupted amplitude values and are substituted for the disrupted values. The apparatus includes an interpolation circuit which includes the shift register and limiter with the memory for adjusting the output signal level of the limiter.

Abstract: A seismic exploration method is disclosed for filtering the signals produced by a detector placed at different depths in a well in response to an emission of acoustic waves from a source on the surface: the signals comprising downgoing wave components and upgoing wave components.The filtering consists in sampling from among the N signals to be processed a group of n signals s.sub.1 . . . s.sub.n detected at respective levels x.sub.1 . . . x.sub.n, in determining the propagation time t.sub.k of the acoustic waves from the level x.sub.1 to each level x.sub.k, in both advancing and delaying the signals s.sub.k by the time t.sub.k in relation to s.sub.1, in adjusting the signals for the effects of the acoustic impedance of the formation, in combining s.sub.1 and the signals s.sub.k thus shifted and adjusted to obtain a sum z.sub.1 ', in calculating a sum y.sub.1 ' of s.sub.1 and of the thus delayed and adjusted signals s.sub.k, and in generating a signal u.sub.1.sup.

Abstract: In the hydraulic fracturing of deep geologic formations for the production of fluid hydrocarbons, and where vertical fractures are formed, a method is described, using seismic geophysical techniques, for determining the azimuth and length of the fractures. This is accomplished by injecting into the formation through the fracture a selected fluid, or producing the fluid hydrocarbons from the formation into the fracture, until the formation, over a selected distance from the walls of the fracture, has a different gas saturation from the condition in the formation farther from the fracture. This condition is mapped by seismic methods.

Abstract: In an acoustic logging system for providing information regarding selected parameters of the wall of a borehole in the earth, and of the rock formation which is adjacent the borehole, in which a single transmit/receive transducer system (T/RTS) mounted on a rotating assembly probes the wall of the borehole in a circular scanning pattern as a function of depth, the improvement which includes at least a second T/RTS mounted on the rotating assembly in known geometrical relation to the first T/RTS, and means to process two or more analog electrical scan signals for transmission over one or more electrical transmission channels in a logging cable. In particular, methods and means are described for transmitting multiple scan signals whereby a higher speed of logging is possible without loss of detail of the logs and without modification of the mechanical system of the logging sonde.