Abstract: A method and system for a Wireless Resilient Routing Reconfiguration linear program or protocol (WR3LP). The WR3LP provides a routing protection scheme that is (i) congestion-free or reduced congestion under a wide range of failure scenarios in point-to-multipoint networks, (ii) efficient in terms of router processing overhead and memory requirement in wireless and point-to-multipoint networks, (iii) flexible in accommodating diverse performance requirements in wireless and point-to-multipoint networks (e.g., different traffic protection levels), and (iv) robust to traffic variations and topology failures in wireless and point-to-multipoint networks.

Abstract: Local detail enhancement (LDE) is an imagery contrast enhancement method applied to visible and uncooled long wave imagery. It enhances local spatial detail through the use of a median based high/band pass filter. The generated detail channel is blended with a histogram-equalized version of the image, creating an image that contains both local detail as well as retaining some amount of global intensity. Retaining global intensity coherency allows for easier target acquisition when compared to fully local forms of contrast enhancement.

Abstract: A modular power supply and distribution system includes a controller and at least one power distribution bus operably connected to the controller. The system includes at least one power distribution bus that distributes electrical power to a plurality of loads. The system further includes a data communication network configured to communicate data between the system and the plurality of loads, power load logic for determining a power load requirement of each of the plurality of loads, hold-up logic for determining a hold-up requirement of at least one of the plurality of loads; and power distribution logic for distributing the electrical power to the plurality of loads based, at least in part, on the determined power load requirement of each of the plurality of loads and the hold-up requirement of the at least one of the plurality of loads.

Abstract: Systems and methods for double-exposure image processing utilizing inversion techniques are provided. The systems and methods of the present disclosure recover single-exposure images from double-exposure images and strain images from double-exposure images.

Abstract: A method, system, and computer program are described for identifying the presence of narrowband signals within a wide instantaneous bandwidth by exploiting the spatial diversity of the received signals using an array aperture to provide detection capability. For example, the method includes receiving and channelizing digitized signals into signals with a narrow bandwidth of interest. The method further includes estimating covariance matrices associated with the signals, determining a set of Eigenvalues for the covariance matrices, and analyzing each Eigenvalue to determine a rank change estimate. The method further includes identifying one or more of the signals that have a positive rank change estimate, computing a beam forming weight and direction estimate for each signal that has a positive rank change estimate, and outputting an indication of the signals that have a positive rank change estimate including one or more of fine timing information, the beamforming weights, and the direction estimate.

Abstract: Embodiments of power efficient radio mixers are provided. A generalized impedance matched low-voltage active mixer circuit technique, which utilizes a plurality of commutator cells and transformers, is disclosed. The low voltage active mixer function is coupled to an impedance matched amplifier allowing for insertion of image rejection filtering between the amplifier and the mixing function. The commutator cells can be driven in parallel by common local oscillator (LO) and intermediate frequency (IF) ports combined in parallel to yield highly linear mixers. A multi-channel receiver with a common impedance matched radio frequency (RF) amplifier driving a plurality of commutator cells with multiple LOs and IFs is also disclosed.

Abstract: A method of mitigating interference in a wireless signal of interest (SOI) received on an active frequency channel due to a common template multi-channel jamming attack includes selecting at least one reference channel from among a plurality of monitored frequency channels in which correlated jamming patterns are present without the SOI. The method further includes generating a plurality of weights according to data obtained from the active and reference channels, and applying an adaptive digital filter to the active channel according to the generated weights. The monitored frequency channels can be centered about the active frequency channel. The selection of reference channels can be varied and optimized. The data from each reference channel can be used to create a single virtual antenna tap or a plurality thereof. Assignment of the active channel can be time-varied to match a hopping pattern of a frequency hopping SOI.

Abstract: A system and method for motion compensation in translational and rotational image smear using a two-axis fast steering mirror and a single-axis gimbal which are controlled simultaneously. A pointing and control module calculates an objective function which can be optimized to find an optimized de-roll rate to compensate for camera boresight rotation in real-time.

Abstract: A continuously adjustable optical beam splitter includes a circular to linear polarization converter, a polarization rotator, and a polarization beam splitter that apportions light between two outputs. The polarization converter can include a quarter wave plate. The polarization rotator can include a mechanically rotated half wave plate or an electronically controlled liquid crystal variable retarder. The light source can be astronomical, reflected LIDAR light, or a laser beam from a remote laser communication node. Also disclosed is a free space laser communication terminal that implements the disclosed optical beam splitter, wherein the optical beam splitter diverts substantially all received laser light to an alignment channel during initial alignment, and then during message communication diverts more than 90%, and in embodiments up to 98%, of the received light to a communication channel, while alignment is maintained by continuing to divert the remaining laser light to the alignment channel.

Abstract: A method and system for nonlinear trajectory shaping guidance law capable of providing a robust guidance solution suitable for multi-mission, multi-mode operations. The nonlinear trajectory shaping guidance law offers (1) a dual layered GL gains calculation: (i) NTS time varying adjustment accounting for engine on/off and L/D variation and (ii) general explicit guidance algorithm based sub-optimal fixed-gain selection while still maintaining its trajectory shaping capability for short range to go missions; (2) flight path angle (FPA) command tracking and following to ensure a high probability of target destruction while minimizing collateral damages; (3) high precision impact point calculation factoring in target location errors or motion and maneuvering uncertainties; and (4) heading error angle minimization.

Abstract: A phase locked loop (PLL) control system includes a voltage-controlled oscillator (VCO) circuit including an inductor and a plurality of capacitors arranged in parallel with the inductor. Digitally enabling or disabling the capacitors in a thermometer coded manner via switches creates tuning states that provide additional frequency range, and each has a limited range of VCO frequency tuning. Slowly ramping the switched capacitance, by implementing the capacitor as a varactor, from one thermal code to the next, provides a wider continuous VCO frequency tuning range for use in the PLL. The slow transition between tuning states allows the PLL to remain in lock, useful under changing operating conditions. Specifically, under changing operating conditions, digital logic detects the PLL tuning control voltage approaching the edge of a VCO band and will add/reduce VCO capacitance effectively transitioning into the adjacent VCO band while the PLL maintains lock via its normal feedback loop.

Abstract: A rollable mast system couplable to an undersea vehicle includes a mast made of a bi-stable composite material configured to roll onto itself in a first state and to stiffen into an elongated stable shape in a second state, and a head structure coupled to a distal end of the mast. The rollable mast system further includes a spool configured to support at least a portion of the bi-stable composite material in its first state and a roller in contact with the bi-stable composite material and configured to pay out the bi-stable composite material from the spool in a direction away from a hull of the undersea vehicle. The bi-stable composite material is in the first state as it passes from the spool to the roller, and the bi-stable composite material is in the second state after it passes the roller.

Abstract: The system and method for a conformal millimeter wave (mmW) cavity backed slot antenna with near positive gain and hemispherical gain coverage. The antenna has a microstrip launch and feed and a surface mount connector. The mmW antenna may have a stripline launch or waveguide launch instead of a microstrip launch. In some cases, the microwave electronics can be mounted on the launch substrate instead of a connector.

Abstract: An identification friend or foe (IFF) transponder includes: an electronic receiver to receive encoded challenges from an IFF interrogator; a processing circuit including a decode circuit to decode the received challenges into encrypted challenges using a time of day (TOD) and/or a cryptographic key, a decrypt circuit to decrypt the encrypted challenges into challenges using the TOD and/or the key, a reply circuit to generate replies to the challenges, and an encode circuit to encode the generated replies using the TOD and/or the key; an electronic transmitter to transmit the encoded replies to the IFF interrogator; and an alert circuit to detect the encrypted challenges from the received challenges without using the TOD or the key, use the detected challenges to determine if the TOD is incorrect and/or the key is wrong, and issue an alert in response to determining the TOD is incorrect and/or the key is wrong.

Abstract: Techniques are disclosed for phase detection in a phase-locked loop (PLL) control system, such as a millimeter-wave PLL. A PLL control system includes a voltage-controlled oscillator (VCO) circuit and a sub-sampling phase detector (SSPD). The VCO circuit is configured to generate an oscillating VCO output voltage based at least in part on an error signal generated by the SSPD. The error signal is proportional to a phase difference between an oscillating reference input voltage and the oscillating VCO output voltage. The SSPD includes a switched emitter-follower (SEF) sampling network, also referred to in this disclosure as an SEF circuit. In contrast to existing CMOS-based techniques, the SEF sampling network allows the SSPD to operate up to higher frequencies, for example, greater than 100 GHz, than possible using a CMOS sampler, and is also compatible with BiCMOS processes, which generally do not have access to advanced small-geometry CMOS.

Abstract: A monolithic microwave integrate circuit (MMIC) presents as a power amplifier including a 9:1 overlay transformer and artificial low impedance transmission lines. The 9:1 overlay transformer effects the output impedance thereof. The artificial low impedance transmission lines behave as inductors without occupying an amount of space equivalent to that of an inductor having similar properties as the artificial low impedance transmission line.

Abstract: Techniques are disclosed for securing data stored on a minimally trusted third-party data store. The techniques include directing all messages for storing data and retrieving stored data through a security server. The security server can be configured to receive encrypted data for storage at a remote data store, decrypt the encrypted data, generate index information for the decrypted data, encrypt the index information, encrypt the decrypted data to produce re-encrypted data, digitally sign the re-encrypted data, and cause transmission of the re-encrypted data and the encrypted index information to the remote data store. To access stored data, the security server can be configured to receive a query for stored data, encrypt the query, cause transmission of the encrypted query to the remote data store, receive a copy of the stored data, process the copy of the stored data, and cause transmission of the stored data to the requesting computer.

Abstract: A power efficient (PE) amplifier includes a cascode amplifier, a transistor amplifier, and a voltage supply. The transistor amplifier includes at least one differential pair of transistors and a plurality of transformers having a primary winding and a tapped secondary winding. The secondary winding is connected across emitters or sources of each transistor pair. The tap of each secondary has a current source. The primary windings of the plurality of transformers are connected in series. The transistor bases or gates are alternating current (AC) grounded. The collector or drain terminal pairs are connected in parallel. The voltage supply is low voltage and supplies a current to the cascode amplifier. The PE amplifier further includes a plurality of current sources which provide a total current to the transistor amplifier. The PE amplifier has, among other things, improved power gain, improved reverse isolation, improved power dissipation, and improved peak differential swing.

Abstract: A co-boresight refractive beam director for a full duplex laser communication terminal includes a chromatic beam steering element, such as a two or three prism Risley prism assembly, and a dispersion compensation mechanism (DCM) inserted in either the transmit or receive path. The DCM adjusts a beam direction of either the transmit or receive laser beam to compensate for a pointing difference introduced by the beam steering element due to a difference between the transmit and receive wavelengths. The DCM can include a tip/tilt mirror and actuator, which can be a commercially available FSM assembly. The beam steering element can be temperature stabilized. Position feedback sensors can increase DCM speed and accuracy. The pointing difference can be calculated and/or interpolated from a pre-established look-up table or fitted curve relating pointing differences to transmit and receive frequencies and the pointing direction of the beam steering element.

Abstract: Techniques are disclosed for generating a featureless low-probability-of-intercept/low-probability-of-detection (LPI/LPD) waveform via a continuously variable symbol rate transmission. A continuous-phase-modulation (CPM) signal can be represented with a phase trellis. During each symbol duration, the trellis is traversed in either a positive or negative direction in a continuous fashion from the starting phase value to the end phase value. The rate at which the trellis is traversed is varied continuously as a time-varying function. The time-varying phase velocity function, or instantaneous symbol rate, is a type of spreading code or secret key shared between the transmitter and receiver. The disclosed techniques can be implemented with CPM compromising the constant-modulus property of CPM signals.