Abstract: A nondissipative circuit for automatic load sharing in parallel converter modules having push-pull power transistors, each transistor having a separate current-sensing transformer and an impedance-adjusting transformer in series with its collector. The impedance-adjusting transformer functions as a current-controlled variable impedance that is responsive to the difference between the peak collector current of the transistor and the average peak current of all collector currents of power transistors in all modules, thereby to control the collector currents of all power transistors with reference to the average peak collector current.

Abstract: Apparatus for enhancing the resolution of a sound detector of the type which includes an acoustic mirror for focusing sound from an object onto a microphone to enable the determination of the location from which the sound arises. The enhancement apparatus includes an enclosure surrounding the space between the mirror and microphone, and containing a gas heavier than air, such as Freon, through which sound moves slower and therefore with a shorter wavelength than in air, so that a mirror of given size has greater resolving power. An acoustically transparent front wall of the enclosure which lies forward of the mirror, can include a pair of thin sheets with slightly pressured air between them, to form an end of the region of heavy gas into a concave shape.

Abstract: An S-band radio frequency subsystem including two transmitters, two receivers and two antennas and capable of connecting either transmitter or receiver to either antenna while permitting simultaneous operation of a transmitter and a receiver. Circulator switches provide selection of a specific transmitter and receiver for connection to either a high gain or low gain antenna. Transmitter output filters, receiver input filters, and diplexers are combined to prevent radiation or coupling of unwanted transmitter and receiver signals and to provide isolation, permitting simultaneous operation of the transmitter and receiver. The filter elements are designed of constant diameter coaxial elements to meet demanding rejection, loss, power-handling and environmental characteristics.

Abstract: An active retrodirective antenna array wherein a reference array element is used to generate a phase reference which is replicated at succeeding elements of the array. Each element of the array is associated with a phase regeneration circuit and the phase conjugation circuitry of an adjacent element. In one implementation, the phase reference circuit operates on the input signal at the reference element, a voltage controlled oscillator (VCO) output signal and the input pilot signal at the next array element received from a transmission line. By proper filtering and mixing, a phase component may be produced to which the VCO may be locked to produce the phase conjugate of the pilot signal at the next array element plus a transmission line delay. The same phase conjugation process occurs at the next element where the proper phase reference is regenerated by mixing samples of the input pilot and transmitted signal.

Abstract: Disclosed is a method and apparatus for reformatting and de-serializing a serially-received sequence of data words, each consisting of a fixed number of binary data bits. A block of nm bits is serially fed into a shift register or serially-connected group of shift registers. In lieu of the (nm - 1)th shift, the bits are rearranged within the shift register in parallel fashion, according to a prescribed scheme. Shifting then continues, until the first bit of each data word appears in the last bit position in the shift register, at which time that data word is shifted in parallel into an output buffer stage, from which it is outputted in parallel, after a fixed delay.

Abstract: A multispectral imaging and analysis system incorporating the use of charge coupled devices or linear arrays of detectors and which is designed to permit on-board analysis of data in real time is disclosed. An imaging system including several arrays of charge coupled devices or linear detector arrays are used to obtain simultaneously spectral reflectance data of different wavelengths for a target area. A plurality of filters each accommodating a particular bandwidth are individually associated with each array. Data from the arrays are read out in parallel and applied to a computer or micro-processor for processing. The micro-processor serves to analyze the data in real time and as may be possible in accordance with hard-wired algorithms. The data are then displayed as an image on an appropriate display unit and also recorded for further use.

Abstract: An azimuth correlator architecture is defined wherein a number of serial range-line buffer memories are cascaded such that the output stages of all buffer memories together form a complete and unique range bin in the azimuthal dimension at any given time. A range bin is automatically read out of the last stages of the registers in parallel on a range line sample-by-sample basis for subsequent range migration correction and correlation. Range migration correction is performed on the range bins by effectively varying the length of a delay register at the output of each range-line buffer memory. The corrected range bin output from the delay registers is then correlated with a Doppler reference function to form an image element on a real-time basis.

Abstract: In infrared spectroscopy utilizing an interferometer, position stepping of the optical path difference in the interferometer must be accomplished quite rapidly in response to a drive signal applied to a moveable mirror in the interferometer which is proportional to the offset distance desired from the previous null point. As the mirror moves in response to this drive signal, effectively getting closer to the new null point, the drive signal is gradually reduced, in response to detected reference laser fringes. At the new null position, the drive signal will effectively be zero. A binary up/down counter drives a digital/analog converter (DAC). The output from the DAC is supplied to the mirror moving means. The fringes generated by a reference laser are detected as the mirror moves, causing the up/down counter to be decremented to its null count, thereby reducing the output of the DAC, as the mirror moves towards its new null position.

Abstract: A free wing attached to a fuselage of an aircraft in a manner such that the wing is free to pivot about a spanwise axis forward of its aerodynamic center. The wing is angularly displaced about the axis by aerodynamic pitching moments, resulting from lift, and is trimmed through a use of a trimmable free stabilizer comprising a floating canard mounted on a strut rigidly connected to the wing and forwardly projected therefrom.

Abstract: An automatic chromosome analysis system is provided wherein a suitably prepared slide with chromosome spreads thereon is placed on the stage of an automated microscope. The automated microscope stage is computer operated to move the slide to enable detection of chromosome spreads on the slide. The X and Y location of each chromosome spread that is detected is stored. At the conclusion of this searching operation, the computer directs the microscope to again sequence through the chromosome spread locations in response to the stored X and Y locations. At this time an operator can view these spreads to determine which ones are worthwhile and which ones are not. He is provided with an accept-reject switch. The microscope stage thereafter again sequences through only the accepted chromosome spreads, and this time a digital photograph of each of the chromosome spreads is made and entered into the computer storage.

Abstract: A conical scan tracking system for spacecraft and radio sources employing a large antenna detects small sinusoidal modulation in received power from a source that is off target with a frequency equal to a very low scan rate, an amplitude proportional to angular deviation of the source from the target, and a phase directly related to the direction the source is off target. The sinusoid is digitally correlated with inphase and out-of-phase (90.degree.) scan sinusoids to obtain azimuth/elevation and hour angle/declination signals which are digitally integrated over exactly one scan period (e.g., 10 to 100 sec) to obtain correction signals for an antenna pointing subsystem.

Abstract: Carrier lifetimes and bulk diffusion length are qualitatively measured as a means for qualification of a P-N junction photovoltaic solar cell by alternately applying high frequency (blue) monochromatic light pulses and low-frequency (red) monochromatic light pulses to the cell while it is irradiated by light from a solar simulator, and synchronously displaying the derivative of the output voltage of the cell on an oscilloscope. This output voltage is a measure of the lifetimes of the minority carriers (holes) in the diffused N layer and majority carriers (electrons) in the bulk P material, and of the diffusion length of the bulk silicon. By connecting a reference cell in this manner with a test cell to be tested in reverse parallel, the display of a test cell that matches the reference cell will be a substantially zero output.

Abstract: An insulation stripper is described which is especially useful for shielded wire, the stripper including a first pair of jaws with blades extending substantially perpendicular to the axis of the wire, and a second pair of jaws with blades extending substantially parallel to the axis of the wire. The first pair of jaws is pressed against the wire so the blades thereof cut into the insulation, and the device is turned to form circumferential cuts in the insulation. Then the second pair of jaws is pressed against the wire so the blades thereof cut into the insulation, and the wire is moved through the device to form longitudinal cuts that permit easy removal of the insulation. Each of the blades is located within the concave face of a V-block, to center the blades on the wire and to limit the depth of blade penetration.

Abstract: Apparatus for demodulation and correlation of a code modulated 10 MHz signal is comprised of a sample and hold analog-to-digital (A/D) converter synchronized by a frequency coherent 40 MHz pulse to obtain four evenly spaced samples A1,B1,A2 and B2 of each cycle of the signal, and means for adding, or subtracting, each sample to, or from, one of four accumulators to form the sums: ##EQU1## where M1 = 10 MHz Reference .multidot. Receiver Code .angle.0.degree.M2 = 10 mhz Reference .multidot. Receiver Code .angle.90.degree.The correlation functions that are used for the range measurements are then computed from the following equations:I = S1.sub.I cos .alpha. - S2.sub.I sin .alpha.Q = S1.sub.Q cos .alpha. - S2.sub.Q sin .alpha.where sin .alpha. and cos .alpha.

Abstract: A technique is disclosed for achieving large populations of metastable spin-aligned He.sub.2 (a.sup.3 .SIGMA..sub.u.sup.+) molecules in superfluid helium to obtain lasing in the vacuum ultraviolet wavelength regime around 0.0800.mu.m by electronically exciting liquid (superfluid) helium with a comparatively low-current electron beam (100-200keV, .ltorsim.10.mu.A) and spin aligning the metastable molecules by means of optical pumping with a modestly-powered (100mW) circularly-polarized CW laser operating at, for example, 0.9096 or 0.4650.mu.m. Once a high concentration of spin-aligned He.sub.2 (a.sup.3 .SIGMA..sub.u.sup.+) is achieved with lifetimes of a few milliseconds, a strong microwave signal destroys the spin alignment and induces a quick collisional transition of He.sub.2 (a.sup.3 .SIGMA..sub.u.sup.+) molecules to the A.sup.1 .SIGMA..sub.u.sup.+ state and thereby a lasing transition to the X.sup.1 .SIGMA.g.sup.+ state.

Abstract: An improved electroexplosive device employs a header having contact pins hermetically sealed with glass passing through from a connector end of the header to a cavity filled with a shunt layer of a new nonlinear resistive composition and a heat-sink layer of a new dielectric composition having good thermal conductivity and capacity. A bridge circuit placed across the contact pins in contact with the heat-sink layer is welded to the pins. The header is inserted into a body for the device and welded for a hermetic seal between the connector end and the bridge end. Layers of igniter and output charges are placed in the body over the heat-sink layer and bridge circuit. A closure disk is then placed over the charges and welded to the body to form a hermetic seal. The nonlinear resistive layer and the heat-sink layer are prepared from suitable comminuted materials by mixing with a low temperature polymerizing resin. The resin is dissolved in a suitable solvent and later evaporated.

Abstract: Apparatus for obtaining significant height information of ocean waves, or peaks of rough terrain utilizing means for compressing the radar signal over different widths of the available chirp or Doppler bandwidths, and means for cross-correlating one of these images with each of the others, where the center frequencies of the images have a spacing .DELTA.f.sub.rO. Upon plotting a fixed (e.g., zero) component of the cross-correlation values R.sup.E (.DELTA.f.sub.rO) as the spacing is increased over some empirically determined range, such as 0 to 1 MHz, the system is calibrated. Thereafter to measure height with the system, a spacing value is selected and a cross-correlation value is determined between two intensity images at a selected frequency spacing, such as 0.1 MHz. The measured height is the slope of the cross-correlation value determined to the spacing value used. Both electronic and optical radar signal data compressors and cross-correlations are disclosed for implementation of the system.

Abstract: A reflex feed system for a dual frequency antenna which may be, for example, one which transmits and receives both S and X-band signals, uses, in place of the dichroic plate normally employed for directing X-band radiation away from the X-band horn a flange about the opening of the X-band horn.

Abstract: A solar energy panel comprises a support upon which silicon cells are arrayed. The cells are wafer thin and of two geometrical types, both of the same area and electrical rating, namely hexagon cells and hourglass cells. The hourglass cells are composites of half hexagons. A near perfect nesting relationship of the cells achieves a high density packing whereby optimum energy production per panel area is achieved.

Abstract: In wireless power transmission systems, in order to provide maximum possible efficiency in the transfer of power, the receiving element of the system must intercept the greatest possible portion of the transmitted energy beam. By having a planar array of receiver elements that are symmetrically located about a physical center, it becomes possible to determine the location on the array of the center of energy of the incident beam. This information is obtained as follows. Sum the output energy of all the receiver elements to the right and left of the vertical center of the array. Determine the difference and sum of these two amounts. Divide the difference by the sum. The result is an indication of the degrees that the center of the incident beam is off in azimuth. Sum the output energy of all the receiver elements above and below the horizontal center of the array. Determine the difference and sum of these two amounts. Divide the difference by the sum.