Abstract: Information about air turbulence and wind shear can be obtained by analyzing the fluctuation of the envelope, at the detector output of a pulse radar, of backscatter from hydrometeors which trace the wind field. Further, under some conditions, radar returns can be identified as being backscatter from weather targets or from the ground or sea. The detector output signal is quantized into one of several class intervals whose boundaries, in mid-range, are in the same ratio. Consecutive radar returns from scatterers at the same nominal range and scan angle are quantized into either the same or different class intervals. The ratio of the number of consecutive quantizations that are different to the number of trials is a measure of the variance of relative velocities at that range and scan angle.

Abstract: A variable flow ejector for use in controlling the amount of bypass flow in a fluid delivery system which includes a pump, a metering orifice and a bypass line for circulating a variable amount of flow from the pump outlet to the pump inlet to control the pressure drop across the orifice. The bypass flow enters the ejector through a variable area nozzle coaxially disposed with respect to a stream from a source of fluid whereby the velocity head of the bypass flow is recovered as pressure head at the pump inlet for increased efficiency. The bypass flow is controlled by varying the area of the ejector nozzle as a combined function proportional to the pressure drop across the orifice plus the time integral of the error in the pressure drop across the orifice.

Abstract: A capacitance-type fluid gage has the probe electrode shaped in accordance with a specified function of container volume and the relative dielectric of the fluid to be gaged.

Abstract: Means for controlling the quantities of the constituents of the combustion charge for an internal combustion engine wherein the controlled quantity is varied at a comparatively high frequency by a relatively small percentage of the presumedly correct quantity. Such variation causes an oscillation of the same relatively high frequency to appear in the output of an oxygen sensor exposed to the engine exhaust. Such sensor oscillations are detected and compared as to proportion with the percentage variation in the controlled quantity. The difference in proportion serves as an error signal to adjust the controlled quantity.

Abstract: System for controlling exhaust gas recirculation in an internal combustion engine having fuel supply means controlled by an electronic control unit. A sensor determines whether the air/fuel mixture of exhaust gases is above or below stoichiometric conditions to generate a feedback signal for the electronic control unit so as tend towards said stoichiometric conditions. Exhaust gas recirculation is controlled by an EGR valve responsive to a command signal. The command signal is equal to the sum of a first signal substantially equal to the control signal generated by an EGR program voltage plus a correction signal, and of a second square wave signal having a given frequency. The correction signal is a function of the amplitude of the frequency component of said feedback, having said given frequency.

Abstract: An aircraft air speed signal is differentiated to provide a signal related to rate of change of air speed. This signal is added to a signal related to aircraft barometric altitude change with the sum signal being compared against aircraft radio altitude to generate warning if the aircraft rate of descent is excessive for the conditions encountered.

Abstract: A microwave landing system employing a phased array antenna for the generation of narrow, scanning guidance beams in which broad beam antennas used for transmitting identification signals, fly-left, fly-right guidance signals and the like with broad coverage are eliminated by applying spoiling phases to the phase shifters of the array thereby broadening the beam shape of the array to a pattern substantially identical to the pattern of a broad beam antenna formerly used. The spoiling phases are applied to the array in the time slots allocated to transmission of broad beam signals and the broad beam signals are then transmitted by the array. The spoiling phases are removed from the array during the time slots allocated to transmission of narrow scanning beams and the narrow scanning beams are then transmitted by the array. Computation of spoiling phases to provide particular patterns for particular antennas is disclosed.

Abstract: A probe for obtaining particulate-free samples of gas from a smoke stack for a power plant or other industrial installation. The probe comprises a coarse filter, with means for periodic cleaning by blowback, protecting the inlet to an inertial filter. A high velocity flow of coarsely filtered stack gas is established through the inertial filter. Sample gas is withdrawn from the inertial filter at a low rate in a direction orthogonal to the gas stream through the inertial filter so as not to disturb particles in the inertial filter stream. The invention eliminates the necessity for frequent maintenance of stack mounted filters or other stack mounted components.

Abstract: A relatively small directional loop antenna adapted for use in an airborne automatic direction finder (ADF) is made to perform like a physically larger loop while being broadly tuned to a mean operating frequency. The total input equivalent noise source is kept low by coupling the loop into an impedance comprised of an active circuit. The active circuit is designed in conjunction with an active feedback circuit into which the ADF sense antenna is fed to maintain a relatively constant phase difference between the ADF loop and sense signals.

Abstract: A coherent demodulator for recovering the phase modulation from an input intermediate frequency signal includes a phase locked loop having switchable frequency and phase detectors. During initial acquisition the phase locked loop frequency is adjusted to be equal to the input intermediate frequency by comparing the loop frequency with the input frequency in the frequency detector and using the resulting error signal to adjust the loop frequency. After acquisition the phase detector maintains the loop frequency phase locked to the input frequency by now using the resulting error signal to adjust loop frequency phase, the error signal from the phase detector being the recovered phase modulation. A second control loop includes a narrow pass filter tuned to the desired frequency of the loop frequency. The error signal from the second loop is summed with the first mentioned error signal to precisely maintain loop frequency.

Abstract: A protected aircraft having a discrete address beacon transponder includes a ground base air traffic control radar beacon system (ATCRBS) interrogator, a collocated discrete address beacon system (DABS) transponder and a directional antenna on the protected aircraft. The protected aircraft synchronizes a local clock with the pulse repetition frequency (PRF) and scan rate of the ATCRBS interrogating his field of interest from which information the protected aircraft can calculate the azimuth angle of responding intruder aircraft with respect to the ground station. By means of his directional antenna the protected aircraft also determines the azimuth of the intruder with respect to itself. Interrogation by the protected aircraft of a collocated ground DABS transponder or a DME or other suitable means of measuring range provides a data base which together with the aforementioned azimuth angles permits the protected aircraft to calculate instantaneous position of the intruder relative to his own.

Abstract: A video processor for Distance Measuring Equipment in which all timing functions including fixed delays are performed by digital counters counting clock pulses from a highly stable source. Search and track operations are conducted by starting a memory counter by a reply from a responser and stopping the memory counter at a time corresponding to maximum range. On a succeeding interrogation cycle the memory counter is started prior to the time a reply at zero range would be received. In this cycle the memory counter begins count with the count it contained when stopped during the previous cycle; the memory counter counts until it reaches a number corresponding to maximum range, stops and initiates a range gate. A reply within the range gate causes the range gate to be repeated at the same time in the following interrogation cycle. A sufficient number of replies within the range gate cause tracking operation to begin. A velocity memory provides continuing tracking during temporary loss of reply signals.

Abstract: AM noise produced by a CW or FM-CW radar transmitter can be cancelled from the radar receiver output by use of a servo system working at video frequencies. A fixed pair of AM sidebands is deliberately added to the source, using a known discrete modulating frequency. A demodulated sample of the total AM noise produced by the source is obtained from a single ended mixer. The servo system adjusts the gain of an amplifier processing this noise, until the level of the demodulated test signal is equal to the level of the demodulated test signal at the output of the radar receiver. The two video signals are then subtracted, cancelling the test tone from the receiver output and incidentally also cancelling the AM source noise from the output of the system.

Abstract: The output of a fast frequency hopping VCO is mixed with the output of a conventional slow acquisition frequency synthesizer to produce an IF which is applied to a frequency discriminator where the IF is compared with a reference IF to provide an error signal which is digitized and stored in a memory. Subsequently, the error signal is applied together with a command signal to the VCO to obtain the desired frequency output.

Abstract: A read-out system for a portable noise dosimeter uses light coupled signals to obtain a noise level read-out display. The light signals are coded to effectively prevent extraneous light signals from causing read-out.

Abstract: Combined keyed AGC and pulse amplitude comparison circuit for use in pulse pair communications system such as DME wherein AGC keying signal is constituted by the second pulse having a predetermined spacing from a first pulse of a pair and wherein said second pulse also provides a reference against which the amplitude of succeeding pulses is compared. Pulses with amplitudes above said reference level are passed to a decoder for determining pulse spacing. The decoder determines which pulse pairs are properly spaced so that the second pulse of a pair can serve as a keying signal.

Abstract: An accessory for a gas concentrator-gas chromatograph system including a split heater block hinged to expose a channel shaped to receive a concentrator column. Quick detachable gas connections are aligned with the block channel facilitating rapid and convenient handling of concentrator columns when a number of similar analyses are to be conducted.

Abstract: The positive portion of the differentiated negative envelope of a detected radar return signal is divided into range cells. The first range cell is taken and doubled to provide a first and succeeding range cell to comprise a Doublet. The Doublets are integrated in a sliding window detector and beam split to supply the target coordinates.

Abstract: A combined loop, sense and communications antenna for aircraft automatic direction finding radio receiver and communications transceiver. A blade-like antenna and a loop antenna are combined in a unitary, streamlined housing of insulating material. The blade antenna serves the dual purpose of providing sense signals to the ADF receiver and of providing a transmitting and receiving antenna for the communications transceiver.

Abstract: In a microwave lens of the Rotman type for a scanning beam antenna a plurality of radiating feed probes are spaced along the focal arc. An illumination function is then commutated around the focal arc by energizing groups of the feed probes simultaneously in accordance with weighting functions to thereby cause the resulting radiated beam to scan in small equally spaced increments while the array factor remains essentially constant. Methods of calculating the weighting functions and feed probe spacing are shown.