Abstract: The digital coherent radar generates its transmitted waveform from a low intermediate frequency (IF) and a local oscillator (LO) by digitally generated waveforms after passing through digital-to-analog (D/A) converters. The LO is increased in frequency using a product multiplier. The IF representation of the transmitted waveform is upconverted using the LO. The transmitted waveform is amplified and passed through a circulator to an antenna. The echos are received through the antenna and passed through the circulator and receiver protector. The received signal is then downconverted to a digital signal and passed on to a processor. Finally, the waveform is reset and restarted by the local oscillator generator, the digital-to-analog converters, and the analog-to-digital converter at the beginning of each pulse. It must be insured that all pulses in a pulse train are identical even though there are deterministic errors in the representation of the transmitted signals desired coherent component.

Abstract: The autonomous survey system (AutoSurvey) is used to automatically maximize area coverage with swath sensors and to minimize survey time while ensuring the collected data meets specified quality constraints. The autonomous survey system (AutoSurvey) evaluates the effects of the environment and system performance on the collected survey data by modulizing the data collection into a series of modules—data collection and error detection, data georectification, data quality validation, swath-edge fit, next-line way point generation, and the autopilot. All of these processes are implemented in near real-time, allowing unfettered survey progress. The data is applied directly between processes, providing operator independent system operation; the autosurvey system directly controls the survey vessel via the autopilot. Through the real-time data acquisition the system provides automation of the operator quality and coverage assessment tasks and also provides quantified data assessment.

Abstract: The technique of shrink fitting technique described herein is used to bond crystalline sapphire pieces to each other, in particular, the shrink fitting of a c-axis sapphire post to a c-axis sapphire puck. The sapphire dielectric resonator is used successfully from cryogenic temperatures to well above room temperature. The shrink fit bond yields a high strength and rigid attachment which can withstand high shock levels. Since there is no loss, the resonator Q is a maximum, being limited by the sapphire loss tangent only.

Abstract: This is a technique using a fiber-optic, wideband array antenna beamformer having cascaded, chirped fiber gratings in a distributed architecture based upon the use of cascaded, fiber-optic, chirped Bragg gratings in a distributed architecture for use in wideband, time-steered array antennas. A wavelength tunable laser serves as a carrier for a microwave signal which is modulated upon it. The signal is corporately distributed to each feed of the array. Each feed then traverses a multi-port optical circulator and is reflected off a number of identical, chirped fiber gratings proportional to their position within the array. The signal is then demodulated and fed to the appropriate antenna element. All gratings are identical with the same length and dispersion (ps/nm). Time-steering is accomplished by tuning the laser wavelength such that the effective reflection point in an individual grating is changed due to the chirped nature of the grating.

Abstract: This device is a broadband, electro-optic modulator comprising an exemplary coplanar waveguide (CPW) electrode structure on an exemplary Mach-Zehnder interferometer. The modulator is formed on a lithium niobate (LiNbO3) substrate that is etched so as to form ridges upon which a gold center electrode and two gold grounded waveguides are deposited upon a buffer layer of silicon dioxide (SiO2) to form a coplanar waveguide electrode structure having a waveguide mode for receiving an electrical signal propagating therethrough in a first direction with a second phase velocity to phase modulate an optical light in the optical waveguide at a frequency in the range from 0 Hz to substantially 40 GHz.

Abstract: A system for instrumenting time sampled predicting interference suppression, particularly in a side-lobe canceller system. Main and auxiliary channel signals are supplied to a canceller loop where correlating weights are sampled just prior to a radar pulse transmission on command of a radar pretrigger pulse. A sampling circuit stores both current and past weights and combines the current weight with the integral of the difference between the current and past weight to form predicting weights over each pulse repetition period. The predicting weights are used to form a translating signal for operating on the auxiliary channel interference signal so that it will cancel the interference in the main channel. By sampling just prior to radar pulse transmission and forming the predicting weights, cross modulation of clutter and antenna scan error can be reduced in order that a side-lobe canceller may be used compatibly with Moving Target Indicators.

Abstract: The onion routing network is used to protect Internet initiators and responders against both eavesdropping and traffic analysis from other users of the Internet. In the onion routing of the invention, instead of making connections directly to a responding machine, users make connections through onion routers. The onion routing network allows the connection between the initiator and responder to remain anonymous. Anonymous connections hide who is connected to whom and for what purpose from outside eavesdroppers.

Abstract: The wideband single-sideband modulator generates single-sideband (SSB) modulation with suppressed carrier utilizing traveling-wave LiNbO3 modulators in a Sagnac loop. In the wideband single-sideband modulator, optical light from a linearly-polarized source is injected into polarization-maintaining fiber (PolMF) where it is split equally via a polarization-maintaining (PolM) directional fiber coupler, resulting in counterpropagating lightwaves in a Sagnac loop. These counterpropagating waves are &pgr;/2 out of phase due to the action of the coupler and remain so when they return to the coupler because they travel equal distances around the loop. Because the coupler is a reciprocal device, if the waves return to the coupler with equal amplitudes, they will recombine and exit the original port toward the polarized light source.

Abstract: A narrow band, high power and coherent source of red light in the red (600-650 nm) spectral region is disclosed. The red light source comprises a first optical source for emitting a first light beam at a first wavelength, a second optical source for emitting a second light beam at a second wavelength, a combiner for combining the first and second light beams to produce a combined beam, and a nonlinear crystal responsive to the combined beam for producing a sum frequency light beam of red light.

Abstract: This invention is directed to a optical fiber embedded in a composite material that, prior to installation, is prepared by cleaning, placing end connectors on at least one end and coating with a protective material. The optical fiber is further coated with an X-ray opaque material compatible with the composite material that allows x-rays, during a machining process, to identify the location of optical fiber when embedded in the composite material.

Abstract: Deployed equipment modules for satellite architecture improvement (DEMSAI) provide ample thermal radiator for area-limited small satellites that typically deploy large-area solar panels from a relatively small mainbody. Rectangular-box-shaped equipment modules are deployed from a compact stowed assembly to offer each of their six side panel exteriors as potential radiator area. Equipment packages are mounted to the interior of these panels. The resultant increase in radiator area translates to an increase in the power-handling capacity of small, fixed-body satellites without resort to deployed radiators.

Abstract: The moving map composer (MMC) is a device that allows a user to manipulate different sources of map data into a single map for presentation on a display. The MMC has an ability to extract a predetermined area of map coverage defined by sets of latitude and longitude points, or non-orthogonal areas of map coverage, the smallest of which is a segment. A bitmap is a representation of an available map coverage for a given area selected by a user having a “set”, or “1” bit to indicate a segment is present, and a “clear”, or “0” bit to indicate a segment is missing. The size of the bitmap is determined dynamically to assure a two-bit buffer zone of clear bits around a polygon's maximum extent. If the user selected polygon crosses one or more maps, the polygon is subdivided into several new polygons.

Abstract: The fluidic drive for miniature acoustic-fluidic pump and mixer is comprised of an acoustic transducer attached to an exterior or interior of a fluidic circuit or reservoir. The transducer converts radio frequency electrical energy into an ultrasonic acoustic wave in a fluid that in turn generates directed fluid motion through the effect of acoustic streaming. Acoustic streaming results due to the absorption of the acoustic energy in the fluid itself. This absorption results in a radiation pressure and acoustic streaming in the direction of propagation of the acoustic propagation or what is termed “quartz wind”.

Abstract: The depthimeter comprises a heave sensor, a mean path compensator and a combiner. The mean path compensator comprises a ranging device which measures the instantaneous distance of the vehicle from a fixed point on the vehicle to ocean surface as a function of time; a range compensator to compensate for signal dropouts in the ranging devices data, for sensor offset angle, and vehicle pitch and roll, thereby providing a signal that contains the vehicles vertical motion and the vertical motion of the sea surface. A low-pass filter within the mean path compensator eliminates the components of the resulting signal due to the motion of the sea surface and the high frequency components of the vehicle's vertical motion, thereby producing a signal that is the mean path of the vehicle, referenced to mean sea level.

Abstract: The valve is designed for the ejection of a plurality of different gases from within the valve, simultaneously, by having a plurality of plenum chambers within the chamber of the valve, and a poppet therein, that are charged with gases under pressure. The gases are sealed within the respective plenum chambers by the action of a spring that urges the poppet against a gas exit port associated with each plenum chamber. Ejection of the gases is accomplished by the application of an electrical current into a coil surrounding the poppet which produces an electromagnetic field that causes a non-ferrous hammer to be driven away from the coil and strike the poppet. Upon being struck by the hammer, the poppet is driven off of the plurality of gas exit ports thereby allowing the gases to be ejected, simultaneously, from the respective plenum chambers into a region of lower pressure.

Abstract: The valve is designed for the ejection of a plurality of different gases from within the valve, simultaneously, by having a plurality of plenum chambers within the chamber of the valve, and a poppet therein, that are charged with gases under pressure. The gases are sealed within the respective plenum chambers by the action of a spring that urges the poppet against a gas exit port associated with each plenum chamber. Ejection of the gases is accomplished by the application of an electrical current into a coil surrounding the poppet which produces an electromagnetic field that causes a non-ferrous hammer to be driven away from the coil and strike the poppet. Upon being struck by the hammer, the poppet is driven off of the plurality of gas exit ports thereby allowing the gases to be ejected, simultaneously, from the respective plenum chambers into a region of lower pressure.

Abstract: Corrosion protection in hollow metal structures is attained by placing an injected, foam-in-place, closed cell plastic polymer foam into an interior of a hollow metal structure, thereby preventing the ingress of foreign matter, such as dirt or water.

Abstract: A gyrotron gun that generates gyrating electron beams in a controllable manner suitable for use in a wide range of gyro-amplifiers and gyro-oscillators is disclosed. The gyrotron comprises first and second means for abruptly changing a magnetic field and which means are positioned between first, second and third field coils. The field coils are operated so as to provide for a desired magnetic field profile that allows for the control of the parameters desired to provide for small-orbit, large-orbit, and linear modes of operation of the gyrotron gun. The gyrotron gun further comprises of a pair of bucking coils arranging near the cathode to independently control the axial velocity spread of the gyrating electron beam.

Abstract: This invention is a communication system utilizing sharply bandlimited waveforms for sampled data communications computed for each sample value in a sequence of data samples. The computed waveform is centered at a sample point, weighted by a corresponding data value, and truncated outside an appropriate time interval. Sampled digital data in a sequence of data samples is received by a computer and scaled according to the value r(tn). A waveform generator, controlled by a computer, generates a sharply bandlimited keying waveform for each data sample and weights each waveform with the data and forms the sum of weighted waveforms to form the output signal in digital form which is converted to analog form. The analog output of the waveform generator is passed through a low-pass filter to filter out any harmonics generated, up-converted to produce a desired carrier frequency which can then be multiplexed, if required, and output as radio frequency (RF) energy which can be received by any standard receiver.

Abstract: A method and apparatus for reducing points of zero intensity, i.e. speckle pattern, emerging from a multimode fiber. The apparatus comprises a beam deflector for rotating an input beam in a conical shape around a launch lens for projecting the beam into the fiber. The rotation of the beam further incorporates the use of two tilting mirrors being 90° out of phase to ensure a conical rotation. The conical rotation of the beam deflector ensures that the lens aberrations, which are rotationally symmetric, do not play a factor in beam alignment into the fiber aperture.