Abstract: A radiation-protection device is provided that includes a substrate and a surface structure formed on the substrate. The surface structure has an arrangement and interacts with radiation and the substrate to at least (a) substantially transmit or attenuate radiation at a wavelength and an energy below a threshold energy, and (b) substantially reflect radiation at the wavelength and an energy above the threshold energy.

Abstract: A DDS system is disclosed that is configured to provide a variable clock delay that allows timing of data coming out of the ROM to be adjusted. In one example case, a DDS system is provided that includes a ROM for storing phase-to-amplitude conversion data and generating digital amplitude values corresponding to respective digital phase values, and delay circuitry for adjusting timing of data output by the ROM to compensate for propagation delay of the DDS system. The delay circuitry may include, for instance, delay elements that can be selected alone or in combination to adjust the timing. The timing can be adjusted, for example, by adjusting delay of a clock signal that clocks one or more ROM pipeline registers. The system may include a phase accumulator and DAC, and adjusting the timing may include adjusting delay of a clock signal that clocks one or more DAC pipeline registers.

Abstract: Techniques are disclosed for optimization of RF converters. The techniques can be employed, for instance, in RF converters implemented in semiconductor materials (system-on-chip, or chip set) or with discrete components on a printed circuit board. In any such cases, the RF converter system can be configured with one or more actuators to adjust performance, one or more sensor to assess the performance (e.g., linearity of RF converter) and parameters of interest (e.g., ambient temperature, and a control block for controlling the sensors and actuators. The configuration allows the RF converter to autonomously self-optimize for linearity or other parameters of interest such as gain, noise figure, and dynamic range, across a broad range of variables.

Abstract: Disclosed is a trust management system for decision fusion in a network. The trust management system includes a detection subsystem having a plurality of sensors, and a plurality of channels. Each sensor of the plurality of sensors detects one of an occurrence and a non-occurrence of an event in the network. The trust management system further includes a fusion subsystem communicably coupled to the detection subsystem through the plurality of channels for receiving a decision of the each sensor and iteratively assigning a pre-determined weightage. The fusion subsystem ascertains a summation of respective decisions of the plurality of sensors and compares the weighted summation with a corresponding decision of the each sensor. The fusion subsystem further updates the assigned pre-determined weightage and determines the presence of the each sensor being one of a compromised sensor and a non-compromised sensor. Further disclosed is a method for decision fusion in a network.

Abstract: Techniques are disclosed for improving the quantum efficiency of photocathode devices. The techniques allow for an increase in the optical thickness of the photocathode device, while simultaneously allowing for an increase in the probability of electron escape into the vacuum of the device. The techniques are particularly useful in detector and imaging. In one embodiment, a photocathode device is provided that has an array of corner cubes fabricated in a surface of the photocathode. The corner cube array is made of the same material as the photocathode layer. The device may be, for example, a detector or image intensifier that operates in the UV, visible, and IR light spectrums, and may further include a gain medium, anode, and readout device. Techniques for forming the device are also provided.

Abstract: In one embodiment, a passive expendable decoy for an aircraft is provided by ejecting passive radiators from the aircraft along a transmission line trailing from the aircraft and excited by a jammer on the aircraft, such that the radiators accelerate under aerodynamic drag forces to the end of the transmission line and couple energy from the transmission line to free space. This provides angular deception to a tracking radar or homing missile since the point of radiation along the transmission line is determined by the instantaneous position of the expendable radiating element.

Abstract: A system and method for mitigating Analog to Digital (A/D) clipping is disclosed. The mean and variance of analog input data are tracked and the bits of A/D are dynamically reassigned to keep the input signal within their range. The quantization levels of A/D are dynamically re-mapped to avoid changes in sensitivity of sensor system. The method is based on random walk statistic and keeps the sensitivity of the sensor system constant. Also the system and method provides a way to mitigate A/D clipping that avoids changing the sensitivity by dynamically re-mapping the quantization levels of the A/D, keeping the sensitivity of the system constant.

Abstract: A fiber-optic connector for connecting an optical fiber to other optical assemblies is disclosed. The fiber-optic connector includes a top plate having a window of similar refractive index and transmission index as the material of an optic fiber to be contained within the fiber-optic connector. The fiber-optic connector also includes a ferrule connected to the top plate via multiple spring-loaded screws. The ferrule includes an interface and an insert. The insert is capable of firmly gripping an optical fiber. In order to reduce Fresnel reflection losses of the fiber-optic connector, the window is pre-coated with an anti-reflective surface on the side opposite an optic fiber to be contained within the fiber-optic connector.

Abstract: A system is provided for the force decay triggered release of a device, the system comprising: a base; a plurality of retention rods extending from the base; a rotationally movable actuator, to which a linear force is configured to be applied, converting the linear force to a rotational force; a plurality of retention pins, the retention pins being coupled to the actuator, and each the pin being removably disposed within a retention rod of the plurality of retention rods, such that a rotation of the actuator withdraw each the pin from respective the rod; a force triggered detent, the detent allowing the rotation of the actuator when the rotational force exceeds a threshold level.

Abstract: An adaptive time delay control system is provided for matching the propagation time delay between two samples of a signal traveling through two independent paths so that they can be coherently combined for additional signal processing functions such as cosite interference cancellers, adaptive interference cancellers and adaptive beam formers. The adaptive time delay control system and associated method advantageously provide improved continuous matching of the two channels over a wider adjustment range while preserving both convergence speed over the full range and minimum jitter upon convergence by using composite autocorrelation functions to control (adjusting) a matching time delay in one channel.

Abstract: Systems and methods provide adaptability in a mobile ad hoc network (MANET), based on an existing protocol, such as adaptive hybrid domain routing (AHDR). The systems and methods are especially suited for fast changing topologies that may change after a reactive route discovery has been completed.

Abstract: A method of detecting gross weight overload of a vehicle comprising the steps of positioning one or more ultrasonic sensors on the vehicle so that said sensors measure the distance to a ground surface, using the sensors to measure height above the ground surface of the vehicle in a non-overloaded condition, adding known weights to the vehicle until maximum gross vehicle weight (GVW) is attained, ascertaining height above the ground surface at this gross vehicle weight (GVW), and continuously measuring height of the ground surface and collecting height above the ground surface data to establish when an overload condition occurs.

Abstract: A system and method for selecting an optimal frequency channel to communicate on in a wireless network is disclosed. The optimal frequency is selected from a predefined set of frequencies for all nodes to communicate on based on an exposure calculation. All underlay nodes collect initial SNR information from initial detection of other nodes and adjust their transmit power for an intended receiver such that the signal is received at the lowest allowable underlay-to-overlay power ratio, thus minimizing exposure. The desired underlay-to-overlay ratio is set based on how much we are capable of cancelling the overlay signal and the SINR at which a signal can be recovered such that the data can be successfully received from the underlay node. The optimal channel selected by this algorithm is the one with the least area of undesired exposure, or least probability of interfering with the primary user. The performance increases as a function of number of nodes, or data points.

Abstract: An adaptive time delay control system is provided for matching the propagation time delay between two samples of a signal traveling through two independent paths so that they can be coherently combined for additional signal processing functions such as cosite interference cancellers, adaptive interference cancellers and adaptive beam formers. The adaptive time delay control system and associated method advantageously provide improved continuous matching of the two channels over a wider adjustment range while preserving both convergence speed over the full range and minimum jitter upon convergence by using composite autocorrelation functions to control (adjusting) a matching time delay in one channel.

Abstract: Embodiments of the invention are directed to methods and apparatus for infrared imagers including fast electrostatic shutters and offset compensation. Fast electrostatic shutters are used for video image correction including image offset compensation where temporal noise and scene nonuniformity are corrected. This method provides a shutterless experience for the user because the image will be blocked for only one frame at a time. A method of manufacturing an electrostatic infrared shutter includes a conductive infrared-transparent substrate, covering it with an insulating layer, depositing adhesive and a thin film stack, delineating a working area, providing contacts, heat-treating the assembly, and making the polymer non-reflective in the infrared.

Abstract: An apparatus and method improves the fault tolerance of a rocket or missile guidance system which includes a resonant sensor. When improper initialization is detected, the resonant sensor is reinitialized, repeatedly if necessary, until normal operation is achieved. Improper initialization is detected by comparing data from the guidance system with pre-specified physical limits to roll, pitch, yaw, and/or other features of the flight scenario. Embodiments can also detect a fault condition due to an error signal from a “Built-in-Test” (BIT) module. The initialization sequence initiated by the invention can be identical to the power-on sequence, or it can be a separate, reinitiating sequence. Subsequent resets are initiated as needed, for example until the burn of the rocket fuel and the associated vibrations have ceased and the resonant sensor has been successfully initialized.

Abstract: Imaging systems, methods, sensor pods, and vehicles having imaging systems. An imaging system can be coupled to a vehicle and can comprise: a plurality of imaging sensors with multiple spectrums; and a processing unit configured to generate an image model in substantially real-time by: warping, fusing, and stitching images; and two or more displays coupled to the processing unit such that the two or more displays can simultaneously each show a different portion of the image model, and such that a user can manually calibrate via the processing unit at least one of the warping, fusing, or stitching. In some imaging systems, imaging sensors are coupled at different elevations relative to a ground vehicle. The present sensor pods can comprise a housing; two or more first imaging sensors having a first spectrum; and two or more second imaging sensors having a second spectrum that is different than the first spectrum.

Abstract: An apparatus for optical spectrometry utilizes a simplified construction, reducing the number of independent optical elements needed while providing a sizeable dispersed spectrum. The apparatus provides a spectral intensity distribution of an input source wherein individual spectral components in the source can be measured and, in some embodiments, can be manipulated or filtered.

Abstract: The replacement and elimination of duplexers in a tightly coupled dipole phased array starts with transmit and receive functions physically separated and having different antenna port feeds. The simple coupling network used with tightly coupled dipole arrays is replaced by a state switch which alternates between a coupling state and a dipole feed connection state. The basic method can be applied to antenna apertures of various kinds, including both linear and dual polarized versions. The ability to locate state switches at various nodes in tightly coupled dipole phased arrays permits flexibility in antenna design and eliminates bulky and lossy components, simplifies the design requirements and allows independent optimization of the components.

Abstract: An electronic countermeasures product includes flexible packaging of diodes that operate in the infrared portion of the electromagnetic spectrum to replace flares, lamps and directed lasers with an inexpensive easily deployed countermeasure systems.