Abstract: This disclosure provides systems, methods and apparatus of establishing a free-space communication link through a medium. The medium can be an occluded environment with increased absorption and/or scattering effects. The free-space communication link includes a transmitter configured to transmit an optical signal at a wavelength suitable for transmission through the medium without suffering excessive optical losses due to absorption and/or scattering effects. The free-space communication link includes a receiver configured to receive the transmitted optical signal. The transmitter-receiver pair is configured to efficiently transmit optical signals at the suitable wavelength over a distance between about 1 mm and about 50 m. The transmitter and the receiver can be configured as portions of a fiber-optic connector assembly that can be used to connect two fiber-optic cables in an occluded environment.

Abstract: A holographic sight is provided having a housing that includes a plurality of holograph sight components. A laser diode mounted in the housing is configured to emit a laser light beam. The light beam is transmitted to an integrated diffraction grating and filter unit which includes a grating and a filter in a single device. The diffraction grating has a grating surface for diffracting the light beam and also diffracting unwanted ambient light transmitted into the housing. The filter is an optical filter contacting at least a portion of the grating. The optical filter is adapted to absorb at least one wavelength of the ambient light to inhibit the ambient light from diffracting into a visible spectrum that might otherwise be viewable to a user looking into the holographic sight.

Abstract: Systems and methods for sensing targets on an opposite side of a wall are disclosed. In some aspects, the techniques include providing an indication to a user that portions of reflected radar signals were blocked by radiofrequency-blocking material at the wall. In some aspects, the techniques include identifying candidate targets as multipath echoes or motion-induced errors based on a correlation map.

Abstract: Detecting timing of a synchronization sequence included in a data stream transmitted in a noisy channel. The synchronization sequence is a known data sequence purposely injected into the data stream for synchronization. A data stream waveform, is obtained from a noisy communication channel. The data stream waveform includes an instance of a synchronization sequence waveform. One or more samples of the synchronization sequence waveform are obtained. One or more samples of a model synchronization sequence waveform are obtained. The model synchronization sequence waveform models an expected waveform for the synchronization sequence being transmitted on the communication channel by applying the synchronization sequence to a model of the communication channel.

Abstract: Optical and RF energy may be provided simultaneously or otherwise across a rotary coupler using separate communication paths. The rotary coupler may be provided with an optical transmission line that passes inside or through the center of an inner conductor of a coaxial RF transmission line that itself extends across the rotational interface/s of the rotary coupler. Both the optical transmission line and the RF transmission line may be positioned at, or close to, the axis of rotation of the rotary coupler. The rotary coupler may be configured to transfer optical and RF energy across rotational interface/s of the rotary coupler using an optical rotary joint positioned inside the inner conductor of a RF channel transmission line that itself is substantially centered at, and in line with, the rotational axis of the rotary coupler.

Abstract: The estimated gain profile of an amplifier can be modified during operation of the amplifier utilizing detected values of the amplification level of signals produced by the amplifier. The amplification levels can be detected at a location that is remote from the amplifier. New expected amplification levels can be determined for corresponding control signal values in the estimated gain profile. Digital filtering such as Kalman filtering can be used to determine the new expected amplification levels. The estimated gain profile can be modified with the new expected amplification levels.

Abstract: Embodiments of strain-balanced superlattice infrared detector devices and their fabrication are disclosed. In one embodiment, an infrared detector device includes a first contact layer, and absorber superlattice region, a wider gap unipolar barrier region, and a second contact layer. The absorber superlattice region has a period defined by a first InAs layer, strain-balancing structure, a second InAs layer, and an InAsSb layer. The strain-balancing structure comprises an arbitrary alloy layer sequence containing at least one constituent element of aluminum or phosphor, e.g., InGaAs, AlInAs InAsP. In another embodiment, the absorber superlattice region has a period defined by a first InAs layer, first strain-balancing structure, a second InAs layer, a first GaSb layer, a second strain-balancing structure, and a second GaSb layer. The first strain-balancing structure includes at least one constituent element of aluminum or phosphor, e.g., InGaAs, AlInAs InAsP.

Abstract: Systems and methods are provided for testing aircraft countermeasure dispenser systems (CMDS) by wirelessly monitoring and controlling wireless countermeasure dispenser testing system units (WCDTs). The disclosed systems and methods may be implemented in one example to allow functions of multiple WCDT units to be simultaneously monitored and controlled in real time via a wireless connection or wireless network connection such as wireless local area network (WLAN) or other short or long range wireless network.

Abstract: A system in which a sending node sends modulated waveform signals to a receiving mode can include the capability to change the waveform type of the modulated waveforms from a current waveform type to a new waveform type. The sending node can generate and send to the receiving node a variable length header that provides the receiving node sufficient information for the receiving node to demodulate modulated waveform signals modulated in accordance with the new waveform type. The variable length header can identify the parameters in a parameter set defining the new waveform type that have different values as compared to the current waveform type.

Abstract: The security level of a communications terminal can be changed during operation. A key loading device can reconstitute a key encryption key from plural split portions. The split portions can be loaded into the key loading device via various interfaces. The reconstituted key encryption key can be used to unwrap wrapped keys stored in the key loading device.

Abstract: A display system is provided to surround a user with an out-the window scene. The system includes a screen structure that is a facetted back-projection dome made up of a polygonal polar top facet surrounded by trapezoidal facets angulated downward from it in an upper facet row. A middle row of facets extends angulated downward therefrom, and a lower row of trapezoidal facets extends down from them. Each facet has video projected thereon by a high definition projector, and to maximize resolution and efficiently use the projector output, the vertical height of each facet makes use of the full vertical field of pixels available from the associated projector. The facets are all tangent to a sphere about a design eyepoint of the dome. The projector resolutions and the size, position and material of the facets are such that the imagery visible on the inside of the dome on the facets is at resolution corresponding to a visual acuity of 20/50 or higher, preferably 20/20, and at or near eye-limiting resolution.

Abstract: Radiation is directed at an object, and radiation scattered by the object is sensed. An angular distribution of scatter in the sensed scattered radiation relative to a path of the radiation directed at the object is determined, and the angular distribution is evaluated. One or more atomic numbers, or effective atomic numbers, of materials composing the object is determined based on evaluating the angular distribution.

Abstract: A drive unit (16) for an aircraft running gear (2) having at least a first wheel (4) and a second wheel (6) on a common wheel axis (A) is characterized in that the drive unit (16) is drivingly coupleable to the first and second wheels (4, 6) such that a direction of longitudinal extension (C) of the drive unit (16) is in a plane orthogonal to the common wheel axis (A).

Abstract: Processes for determining imperfection offsets between an antenna and the platform to which the antenna is coupled, where the imperfection offsets are unknown offsets due to imperfections such as manufacturing imperfections. The platform can include an orientation mechanism that provides the orientation of the platform, and the imperfection offsets can be between the antenna and the orientation mechanism. The processes can include determining two different relative pointing vectors that correspond to a detected peak strength of a test signal transmitted between one or more targets and the antenna. The processes can further include utilizing an optimization process to determine the heading, pitch, and roll of the imperfection offsets from the two different relative pointing vectors.

Abstract: An aircraft electronic device retention mechanism and method of removeably supporting an aircraft electronic device having first electrical contacts within a cockpit having compatible second electrical contacts includes a base that is generally configured to the size and shape of a surface of the electronic device and at least one lever that is mounted by a pivot to the base. The lever(s) has an engaging portion that is adapted to engage an engaged portion of the electronic device and an actuation portion. The actuation portion is adapted to rotate the lever(s) about said pivot between a first orientation in which the engaging portion retains the engaged portion and a second orientation in which the engaging portion does not retain said engaged portion. A manual actuator is connected with the actuation portion of the pivot.

Abstract: Methods and apparatus for integrating a table with at least one X-ray source for medical imaging of patients. The apparatus comprises a table on which a patient may be placed, at least one X-ray source configured to generate X-rays at a plurality of X-ray source locations along a linear direction, wherein the at least one X-ray source is arranged to generate the X-rays such that at least some of the X-rays pass through a portion of the table in addition to passing through a portion of a patient placed on the table, and at least one detector array comprising a plurality of detector elements and arranged to detect the at least some of the X-rays passed through the portion of the patient placed on the table, wherein the at least one detector array comprises detector elements arranged in a two-dimensional configuration. Iterative reconstruction techniques may be used to reconstruct an image from X-ray data detected using the at least one detector.

Abstract: Embodiments of the present disclosure are directed to infrared detector devices incorporating a tunneling structure. In one embodiment, an infrared detector device includes a first contact layer, an absorber layer adjacent to the first contact layer, and a tunneling structure including a barrier layer adjacent to the absorber layer and a second contact layer adjacent to the barrier layer. The barrier layer has a tailored valence band offset such that a valence band offset of the barrier layer at the interface between the absorber layer and the barrier layer is substantially aligned with the valence band offset of the absorber layer, and the valence band offset of the barrier layer at the interface between the barrier layer and the second contact layer is above a conduction band offset of the second contact layer.

Abstract: An apparatus includes an extendable wand, and a sensor head coupled to the wand. The sensor head includes a continuous wave metal detector (CWMD) and a radar. When the wand is collapsed, the wand and the sensor head collapse to fill a volume that is smaller than a volume filled by the sensor head and the wand when the wand is extended. Frequency-domain data from a sensor configured to sense a region is accessed, the frequency-domain data is transformed to generate a time-domain representation of the region, a first model is determined based on the accessed frequency-domain data, a second model is determined based on the generated time-domain representation, the second model being associated with a particular region within the sensed region, and a background model that represents a background of the region is determined based on the first model and the second model.

Abstract: The systems and methods described herein disclose creating an Intensity Based Colormap by interweaving different Hues between two end points (e.g., black and white) with increasing Luminance. An Intensity Based Colormap may be used to convert Computer Input image data using a Computer Machine encoded with an Intensity Based Colormap.

Abstract: The present invention is generally directed to using code division multiplexing (CDM) on the beacon and traffic channels while lowering the power of the beacon channel so that it rides under the traffic channel and becomes very difficult to detect. In this way, the beacon channel can contain sensitive information for decoding the traffic channel while remaining hidden from unintended recipients. By hiding the beacon channel, the CDM technique can be particularly beneficial in adaptive waveform systems where sensitive traffic channel acquisition information is regularly transmitted to the receiver.