Abstract: A multiple frequency laser technique for enhancing the detection of discrete targets amid a clutter background while also increasing the range performance or power limits of the laser type radar. Each of a plurality of laser oscillators cooperates by heterodyned phase-lock means to provide a mutually exclusive one of a plurality of mutually coherent frequencies, whereby the transmitted continuous wave energy comprises a coherent pulse train.

Abstract: An apparatus is described which is responsive to a sequence of received data-compacted pixels representative of a coarse two-dimensional image of a remote scene for reconstituting picture point intensity signals representative of the smoothly shading in of the coarse image.

Abstract: A method and apparatus for the smoothing and singularity detection of the ridge contour data of a fingerprint image for classification in an automatic fingerprint identification system. A template scanning window is passed electronically over a digital matrix of ridge contour data to generate a set of correlation values corresponding to each contour data element and to a plurality of reference angle vectors. The correlation values are processed for determination of peaks and valleys. Tests are conducted to determine whether the relative values of peaks and valleys and the relative spacing between peaks and valleys satisfy certain threshold criteria for reliable extraction of fingerprint singularity points for classification. The resultant data, representing the number of correlation peaks and the direction of each, defines the location and angular orientation of cores and deltas of a fingerprint.

Abstract: In a binary phase-coded pulse compression type pulsed energy system, means for synchronously transmitting two separately binary coded signals, the code for each signal having an autocorrelation function exhibiting a maximum synchronously occurring with that of the other coded signal, the two autocorrelation functions, when combined, being mutually cancelling except at the synchronous occurrence of the maxima of the autocorrelation functions.

Abstract: An automatic system is described wherein pattern representations of epidermal ridges, such as fingerprints, are uniquely described by the extraction of specific information. Specific information such as ridge contour data, describing the ridge flow in the fingerprint pattern and minutiae data, principally describing ridge endings and bifurcations, are identified and extracted from the fingerprint pattern. Topological data, identifying singularity points such as tri-radii and cores, as well as ridge flow line tracings related to those points are extracted from the ridge contour data. The extracted information is then utilized by the system to automatically perform classification of the fingerprint pattern and/or matching of the fingerprint pattern with patterns stored in a mass file. Identification is automatically achieved by comparing the extracted information with the information stored in the mass file corresponding to previously identified fingerprint patterns.

Abstract: A device for correcting charge-transfer inefficiency-induced distortion in charge-transfer-device analog shift registers. The shift register successively samples a data line of interest, a voltage reference source and a null input. A preselectively modeled filter, having a gain control input, cancels the "tail" or terminal data smear induced by the charge-coupled device, the gain of which filter is adjusted during response of the charge-coupled device to a sampled null input. Additional compensation of the shift register output is also provided for gain changes thereof and bias content.

Abstract: A device for correcting charge-transfer inefficiency-induced distortion in charge-transfer-device analog shift registers. The shift register successively samples a data line of interest, a voltage reference source and a null input. A variable time-delayed, synchronous inverter provides a-c coupling of the register so as to avoid bias content effects, and cancels the "tail" or terminal data smear induced by the charge-coupled device, the delay or phase of which inverter is adjusted during response of the charge-coupled device to a sampled null input. Additional compensation of the shift register output is also provided for gain changes thereof.

Abstract: A system which, in one exemplary embodiment, comprises first means responsive to minutiae of first and second fingerprints for selectively generating a plurality of neighborhood comparison signals indicative of the closeness of match and coordinate displacements between minutiae neighborhoods of the first and second fingerprints, and second means responsive to the neighborhood comparison signals for developing an output signal indicative of the relative closeness of match of the first and second fingerprints.

Abstract: In an airborne armament fire control prediction computer, apparatus for computing smoothed inertial velocity and acceleration components of an observed target in a three-dimensional Cartesian coordinate system. A target tracking sensor mechanization is provided which generates target position, velocity, and acceleration data components in an inertially-stabilized Cartesian coordinate system, whereby improved closed-loop pilot-aircraft weapon control system dynamic stability and accuracy result. Target sensor dynamic tracking accuracy improvement and noise reduction are also obtained by virtue of such inertially stabilized tracking mechanization.

Abstract: In a ring laser type gyro, laser optics adjustment means comprising a duo-mode bimorph device for separately controlling each of the optical length and alignment of the gyro laser optics.

Abstract: An analog to digital converter wherein an incremental pulse width modulator controls first and second modes of operation of a bridge network of switches such that the bridge network of switches passes a precision current from a current source into a summing input of an integrator during the first mode of operation and away from the summing point of the integrator during the second mode of operation. The bipolar precision current from the bridge network of switches is summed with an analog current at the summing input of the integrator to cause the integrator to develop a voltage signal proportional to the integral of the sum of these currents. In response to the voltage signal and to clock pulses, the incremental pulse width modulator precisely controls the first and second modes of operation of the bridge network of switches and enables an output circuit to generate a digital representation of the amplitude of the analog current.

Abstract: In a laser gyro, laser optics adjustment means comprising a mirror within the laser optics of the gyro and mounted upon a three-terminal duo-mode bimorph device for duo-mode modulation of the laser optics. A two-stage differential amplifier is responsively coupled to a source of two mutually phase-coded reference signals for separately dithering each mode of the duo-mode bimorph device, each stage being further responsive to a mutually exclusive one of a first and second synchronously detected photodetector output of the laser gyro whereby closed loop control of the laser optics is effected.

Abstract: A forward observer directs a pulsed neodymium laser illuminator in the direction of a target to be marked. A detector-receiver which is fixedly mounted to an attacking aircraft detects the reflected laser energy and determines its direction of incidence. Four indicator lights are projected onto a conventional gunsight combining plate together with a crosshair reticle. The lights provide the pilot with steering signals which will permit him to aline the crosshairs and the target.

Abstract: In a multi-element array of laser oscillators, each having a control input for adjusting the output laser light frequency thereof, apparatus for phase and frequency locking each laser oscillator of the array to a reference laser oscillator. An optical phase shifter cooperates with the reference laser oscillator and with a radio frequency source to provide a local oscillator energy source. Mixing of the local oscillator energy with that of a respective one of the array oscillators by photodetector and then phase detection of the mixed or down-converted signals, relative to the radio frequency source, provides a control signal for phase and frequency control of the array oscillator.

Abstract: A ring laser gyro body is rotationally dithered about a single cantilevered flexure pivot and its rotational vibration is isolated by a counter-rotating mass driven from the gyro body by a tightly coupled linkage.

Abstract: An apparatus is described for detecting minutiae in a two-dimensional binary image. In a preferred embodiment a two-dimensional binary data bit stream of an image is enhanced in an enhancement circuit by pore-fill and line-thin operations. The enhanced binary data bit stream is then applied in parallel to first and second detectors which detect minutiae and extract the X, Y and .theta. coordinates of each minutiae detected in the enhanced binary data bit stream.

Abstract: A system for detecting one or more keywords in continuous speech is disclosed wherein a speech processor extracts a plurality of analog speech parameters from the input continuous speech, an STV (Spectral Time Vector) generator circuit selectively converts the plurality of analog speech parameters into digitized spectral parameters, an asynchronous correlation circuit continuously correlates sequences of the digitized spectral parameters with stored reference mask templates representative of subelements (dyads or triads) of one or more desired keywords in order to produce continuous correlation data, and a decision function circuit is responsive to the correlation data for developing an occurrence decision output for each desired keyword that is detected.

Abstract: The invention is directed to an electrostatically supported ball type gyroscope pickoff system for determining the attitude (i.e., angular orientation) of the ball spin axis relative to the gyroscope case for any arbitrary attitude. The gyroscope case is provided with a set of electrostatic electrodes arrayed in three-dimensional space. A levitating electric field is maintained between the ball and the electrodes. The ball is so constructed as to be unbalanced about its spin axis. Under such conditions, as the ball spins, it orbits, and its surface alternately advances towards and recedes from any given electrode at the spin frequency, producing a field modulation signal. The phase pattern of the modulation signals at the several electrodes is a unique function of the attitude of the spin axis relative to the electrodes. Means are provided for processing the modulation signals so as to determine the attitude of the ball.

Abstract: A set of three or more acoustic transponders positioned below the surface of the ocean is provided with logic circuitry that enables location of transponder positions merely by listening to transponder signals and also enables location of an unknown receiving station merely by listening to transponder signals. The transponders are self-synchronizing to eliminate the need for precision timing over long periods. In a first mode, each transponder transmits a signal to the surface and retransmits upon receipt of its echo to thereby provide depth data. In a second mode the transponders transmit to each other and retransmit an acknowledge signal upon receipt of a reply from one of the other transponders. This provides data to enable a remote station to calculate distances between the respective transponders.

Abstract: This invention relates to a communication system wherein a plurality of stations can communicate with each other, without going through a central switchboard; and more particularly to such a communication system that is as private as possible -- the commmunication system having, in addition, the capability of conference calls and a command-override.