Abstract: An air-to-ground tracking guidance system wherein a tracker/illuminator and a terminally guided seeker are utilized. Target track is initially established by the tracker/illuminator which also provides a target illuminating signal. Semi-active tracking utilizing the reflected target illuminating signal is employed by the seeker after launch. During this period of operation, the seeker is prevented from tracking the tracker/illuminator by means of a unique guard radiation system. The semi-active mode is supplemented by an active mode in which the seeker tracks reflections of a target illumination signal emitted therefrom and a passive mode during which the seeker tracks the radiometric thermal emission from the target. While in the semi-active mode, the seeker establishes a range track that is independent of the semi-active mode of operation. This permits the seeker to automatically convert the mode of operation to active and passive at the desired positions along the seeker's track.

Abstract: A full or partial rotational, substantially zero friction electrical conductor assembly conducts the electrical currents of a large number of electrical circuits between a pair of relatively rotatable members in a minimum axial length. A plurality of concentric, annular, radially spaced gaps are formed between corresponding concentric, concave surfaced, electrically conductive rings affixed to the members, such that a large number of circuits may be accommodated in a reduced axial length assembly. Resilient, filamentary conductor loops are disposed between the conductive rings, and the loops contact, roll on, and are captured by the concave surfaces of the conductive rings, thereby providing electrical continuity between the relatively rotatable members. The conductor loops are sealed within individual structural enclosures, thus, providing an environmentally clean and rugged assembly.

Abstract: An optical pulse-forming switch includes a pair of spaced apart photodetectors and a rotatable shutter arranged to permit sequentially illuminating first one photodetector and then the other, depending on the sense of rotation, to produce out-of-phase pulse trains. The optical pulse-forming switch is interfaced with a pair of synchronized flip-flops and a phase detection counter control circuit which senses rotation extent and direction. The counter control circuit drives a counter that stores the number of passed angular increments and stores direction of rotation, the counter being interrogated and reset at regular time intervals. Thus, the input shaft rotation is converted into a digital quantity by maintaining a running summation of counter values. The operator reference indicator is accordingly brought up to date following each input conversion.

Abstract: A median detector receives serially a series of numbers, the median of which is to be determined. The detector includes an ordered plurality of registers and a like plurality of comparators each associated with a different register. The respective comparators are responsive to the respective values of numbers already in the registers and to values of new numbers in the series to rank the numbers in numerical order in the registers. After the ranking, the register associated with the middle number in the series contains the median value.

Abstract: In a device having a synchro resolver and a microprocessor, the apparatus of the present invention utilizes a pulse excitation technique for converting a synchro output signal to a digital format. A pulsed waveform is selectively applied to the input windings of synchro resolver and output voltages are induced in the output windings. A sample and hold circuit is selectively enabled and selectively coupled to the output windings of the synchro resolver, and the sampled output signal of the output windings is converted into a digital format via an analog-to-digital converter.

Abstract: A dome antenna including a dome of solid dielectric material and scannable feed array positioned in the base plane thereof. The dielectric material of the dome constructed to provide a dielectric constant that varies with the perpendicular distance from the base plane. Rays emanating from the base plane are continuously refracted within the dome and refracted at the surface thereof, the interface with free space, to accomplish sufficient a scan angle amplification for scanning beam to the horizon and below.

Abstract: A fine/coarse data selector apparatus for aircraft flight control systems and instruments is manually adjustable in either an incremental fine mode or an uninterrupted slew mode by means of a high resolution gear change clutch means which eliminates any gear mesh alignment and resulting undesired signal transducer transients associated therewith.

Abstract: The interleaved dipulse sequence generating apparatus decomposes the data pulses of a data transmission or recording channel into pairs of spaced apart subpulses denoted as dipulses. The dipulses are interleaved or nested with respect to each other and without interference therebetween to provide an interleaved dipulse sequence signal which is conveyed on the channel.

Abstract: A wide band surface wave transducer is provided with means for launching a surface acoustic wave on a non-piezoelectric material by first launching the surface wave at the surface of a piezoelectric material spaced apart from the aligned non-piezoelectric element. A mechanical coupling array provides energy transfer between the two wave propagating surfaces.

Abstract: Geothermal deep well energy extraction apparatus is provided of the general kind in which solute-bearing hot water is pumped to the earth's surface from a subterranean location by utilizing thermal energy extracted from the hot water for operating a primary turbine-motor for driving a primary electrical generator at the earth's surface, the solute-bearing water being returned by a reinjection well. A surface-located auxiliary turbine-pump combination with both turbine and brine pump elements acting in series with down-well counterparts to furnish the pressure necessary for reinjection of the brine.

Abstract: The outputs of a three-wire synchro are applied to a multiplexer which provides the multiplexed synchro outputs to an amplifier and demodulator. The demodulated synchro outputs are applied to a demultiplexer whose outputs are filtered to provide demodulated d.c. voltages corresponding to the synchro output signals. The demodulated d.c. voltages are applied to a conversion circuit for providing the sine and cosine of the angular position of the three-wire synchro device. The multiplexer, demultiplexer and demodulator are synchronized by the synchro a.c. reference signal.

Abstract: In a magnetic compass compensation system suitable for use within a ferrous land vehicle, a secondary magnetic sensor senses, the total magnetic field as components along a three axis system drawn vertical, lateral and transverse to the ferrous vehicle. Compensation signals corresponding to the permanent and induced magnetic fields of the vehicle are isolated from the total magnetic field. The compensation signals are applied to compensation coils surrounding a primary magnetic sensor for providing an output equivalent to the horizontal components of the earth's undisturbed magnetic field.

Abstract: In a voltage conversion circuit, comprising a source of input DC voltage, an input voltage switching circuit and a transformer having a primary winding coupled in series with the switching circuit and input DC voltage for periodically receiving DC voltage thereat and having a secondary winding connected to a DC output circuit for producing a DC output voltage of a given polarity, the transformer primary normally undesirably produces a switching circuit damaging voltage spike of a polarity opposite the given polarity upon the voltage being removed from the transformer primary by the switching circuit. A voltage suppression circuit is responsive to the voltage polarity reversal in the transformer primary, which occurs when the input voltage is removed therefrom for storing the energy which would otherwise produce the voltage spike.

Abstract: A deep well pumping apparatus utilizing a geothermal source of energy is disposed within or above a stratum having a cool irrigating fluid, and an associated heat exchange unit is disposed within a stratum having the geothermal source. An organic working fluid is conveyed under pressure through the heat exchange unit and applied as a gas to a turbine assembly operatively coupled to the pump. The spent working fluid and cool irrigation fluid are then conveyed to the surface.

Abstract: An apparatus and method for detecting the polarization of signals reflected from targets immersed in clutter. Signals reflected from targets illuminated with quasimonochromatic electromagnetic signals such as FMCW radar are received by antennas responsive to orthogonally polarized components of the reflected signals. These received orthogonal signal components are then modified such that one component is phase shifted with respect to the other signal components, and the amplitudes of the signal components are varied according to predetermined angles of polarization. The resulting signals are further analyzed in a processor which detects the polarization of the reflected signals by estimating the Stokes parameters for the reflected signal. The Stokes parameters may then be used to generate detection criteria that are compared to a predetermined threshold level.

Abstract: An apparatus and method for detecting the polarization of signals reflected from targets immersed in clutter. Signals reflected from targets illuminated with quasimonochromatic electromagnetic signals such as FMCW radar are received by antennas responsive to orthogonally polarized components of the reflected signals. These received orthogonal signal components are then analyzed in a processor which detects the polarization of the reflected signal by estimating the Stokes parameters for the reflected signal. The estimated Stokes parameters may then be used to generate detection criteria that are compared to a predetermined threshold level. The presence of the target is indicated when the detection criteria level exceeds the level of the predetermined threshold.

Abstract: A voltage conversion circuit includes a transformer having a primary winding and a secondary winding with an output terminal. The primary winding is coupled in series with a switching circuit across a source of DC potential. The switching circuit periodically interrupts the DC potential to the primary winding and upon the interruption the primary winding undesirably produces a switching circuit damaging voltage spike. A voltage suppression circuit is responsive to the voltage polarity reversal in the transformer primary, which occurs when the input voltage is interrupted thereto for transferring the energy, which would otherwise produce the voltage spike, to the converter output terminal to add energy thereto. When the switching circuit is non-operational no voltage reversals are present in the transformer and no voltage is therefore passed to the output terminal.

Abstract: A detection system wherein the signal levels of a plurality of resolution cells on either side of the resolution cell of interest are compared to the signal level therein. Runs of resolution cells with signal levels that exceed or do not exceed the signal level of the resolution cell of interest are taken and a run count is determined which is utilized to establish a signal detection.

Abstract: The invention provides a temperature-insensitive, reflective acoustic wave signal processor employing a trio or reflective arrays disposed effectively to rotate the direction of propagation of the acoustic wave through 180 angular degrees so that the acoustic wave in a preferred embodiment reaches the output transducer flowing in the opposite parallel direction as when launched by the input transducer.

Abstract: A gyro rotor is freely suspended in a housing for simultaneous rotation about a spin axis and a pair of precession axes in turn orthogonal to the spin axis, by a pair of magnetic suspensions spaced along the spin axis. Each magnetic suspension comprises a magnetically permeable stator member and a cooperative magnetically permeable rotor member relatively arranged so as to define axially spaced annular magnetically permeable gaps. Each magnetic suspension includes a permanent magnet for producing a fixed or passive magnetic flux in each gap and an electromagnet coil for producing a controllable or active magnetic flux in each gap. The passive flux provides passive stabilized suspension of the rotor parallel to two of said axes, while the active flux provides active stabilized suspension of the rotor parallel to the third of said axes using a closed servo loop.