Abstract: A dual-spectrum photocathode capable of emitting photo-electrons into a first vacuum space includes a first photodetector array formed using a first optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a first spectral band. The dual-spectrum photocathode also includes a second photodetector array formed using a second optoelectronic material that generates photo-electrons responsive to incident electromagnetic energy in a second spectral band that is different from the first spectral band. The first spectral band may include the visible electromagnetic spectrum between 390 nanometers and 700 nanometers and the second spectral band may include the short-wave infrared (SWIR) electromagnetic spectrum above 900 nanometers.

Abstract: An enhanced vision system includes an image intensifier that includes a phosphor screen. The phosphor screen includes a thin-film phosphor layer deposited, patterned, transferred, or otherwise disposed on the substrate using a thin-film deposition technique. A conductive layer is deposited across at least a portion of the phosphor layer. The relatively smooth morphology of the phosphor layer beneficially permits the use of a relatively thin conductive layer. The use of a relatively thin conductive layer advantageously reduces the operating voltage between an electron multiplier and the phosphor screen. A secondary electron emitter may be disposed across at least a portion of the conductive layer.

Abstract: A transmit signal can be distorted with non-linear distortion, and one or more characteristics of the non-linear distortion can be periodically changed in accordance with a change key. The transmission received at a receiver can thus comprise a severely distorted version of the transmission of the transmit signal. A receiver with the same change key can recognize and decode the transmission, but it can be extraordinarily difficult for receivers that lack the change key to detect and decode the transmission. The transmission can be a communications while jamming (CWJ) transmission. The CWJ transmission can contain a coded message that can be decoded only by friendly RF receivers, and the CWJ transmission can also jam unfriendly RF receivers that lack a change key for decoding the coded message.

Abstract: A method of estimating the location of the source of a signal of interest (SOI), includes the steps of: (a) sensing a plurality of directional samples of the SOI by using at least one signal receiving system at disparately located signal receiving locations; (b) with at least one of the signal receiving systems, measuring the power variable of the received SOI; and (c) processing the sensed directional samples of the SOI in combination with the power variable measurement of the SOI to estimate the location of the source of the SOI.

Abstract: Reconfigurable payload systems (RPS) and methods of configuring and using the same with operational load envelopes are disclosed that may be employed to enable external aircraft payloads to be rapidly interchanged or swapped out together with associated internal equipment within a given aircraft so as to modify or change payload capability of the aircraft, e.g., to meet a particular mission and/or to enable use of future payload types as they are developed. The RPS and associated methods may be implemented to allow multiple different payload systems to be swapped in and out on a given aircraft as required based on needs for a given mission.

Abstract: Methods, systems, and apparatus for transmitting a first set of continuous wave (CW) signals, where each CW signal of the first set of CW signals has a first signal frequency and the transmitter is turned off between transmission of each CW signal of the first set of CW signals. For each CW signal of the first set of CW signals, receiving a reflection of the CW signal, and selecting an analog to digital (A/D) sample of the reflection of the CW signal that does not contain ground reflections by selecting the A/D sample based on timing from the transmitter being turned off after transmission of the CW signal. Integrating the selected A/D samples from each of the CW signals of the first set of CW signals to obtain a single A/D sample for the first set of CW signals.

Abstract: A transmitter or receiver can include a phased array antenna system in which multiple characteristics of a transmitted or received beam can be controlled electronically. For example, in embodiments that include a transmitter, dual outputs of N signal modifiers can be connected to orthogonal inputs of N dual-orthogonally polarized antenna elements. Each signal modifier can modify the amplitude and phase of a communications signal in two parallel signal paths to produce two signal components each of which is an amplitude-modified/phase-shifted version of the communication signal. Multiple characteristics of the combined beam can be simultaneously controlled by setting the amplitude and/or phase-shift parameter values in the dual signal paths in the signal modifiers to combined values that individually affect each of the multiple characteristics of the combined beam.

Abstract: A block of ordered data elements comprising a plurality of sub-blocks each of which is to be processed by a different processing module in segments of the data elements having a particular length characteristic can be received in parallel streams on parallel communication channels. The data elements in each stream can be received and directed to the corresponding processing module. The tail of a segment split between two of the streams and received earlier in time than the corresponding head of the split segment can be buffered until the head is received on the other stream. The head and the tail of the split segment can then be processed as a whole segment in a corresponding processing module.

Abstract: A surface wave antenna system is presented. The surface wave antenna system is configured to be coupled to a surface and includes an antenna and a radiation modifier. The radiation modifier includes a material having a graded dielectric constant. A final portion of the radiation modifier includes material having a dielectric constant that produces a signal phase velocity in signals emitted from the radiation modifier that is substantially equal to a phase velocity of signals on the surface.

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: A method and apparatus for controlling mobile/remote recording devices in a decentralized manner and auto-triggering such devices in the event that one of them is operating in a recording mode. In this way, other such devices can be made to support and augment the recording in an automated way, without requiring an operator to manually turn on his or her devices and without requiring a central controller to control far-flung devices.

Abstract: A fault detection system is provided for a display system including an AMLCD. A video processor embeds encoded fault detection data within the digital video stream that is sent directly to the AMLCD. The fault detection data is embedded in such a manner that it is not displayed by the AMLCD. The fault detection data in the digital video stream received by the AMLCD is detected by the AMLCD and is then sent back to the video processor. The video processor compares what was sent with what is received to determine whether there is a difference which may be indicative of a fault in the AMLCD or the path of the digital video stream. As an additional check, the AMLCD may send timing error data to the video processor indicating whether the AMLCD is working properly. The video processor generates and outputs a fault flag to initiate a corrective action if a fault is detected in the AMLCD and/or the path of the digital video stream.

Abstract: Methods, systems, and apparatus for transmitting a first set of continuous wave (CW) signals, where each CW signal of the first set of CW signals has a first signal frequency and the transmitter is turned off between transmission of each CW signal of the first set of CW signals. For each CW signal of the first set of CW signals, receiving a reflection of the CW signal, and selecting an analog to digital (A/D) sample of the reflection of the CW signal that does not contain ground reflections by selecting the A/D sample based on timing from the transmitter being turned off after transmission of the CW signal. Integrating the selected A/D samples from each of the CW signals of the first set of CW signals to obtain a single A/D sample for the first set of CW signals.

Abstract: A cluster cap sealing mechanism and method for a Geodesic construction. A packaging for a sealant placed in a ring wherein the ring is a sealant delivery device for providing a predetermined volume of sealant to the joints of the Geodesic construction.

Abstract: A multilayer printed circuit board comprising: i) a plurality of circuit board layers disposed in parallel planes to one another; ii) an outer via forming an electrical connection between a conductor contact on a first circuit board layer and a conductor contact on a second circuit board layer, wherein the outer via has a hollow central core; and iii) an inner via formed within the hollow central core of the outer via. The inner via forms an electrical connection between a conductor contact on a third circuit board layer and a conductor contact on a fourth circuit board layer. The inner via and the outer via are substantially concentric cylinders.

Abstract: An electronic system comprising: 1) an antenna; 2) a transmission line coupled to the antenna; 3) RF electronics circuitry coupled to the transmission line that is sensitive to a high frequency EMI/RF signal on the transmission line; and 4) a protection circuit comprising passive mode circuitry operational when the electronic system is powered off and active mode circuitry operational when the electronic system is powered on.

Abstract: A surface wave antenna system is presented. The surface wave antenna system is configured to be coupled to a surface and includes an antenna and a radiation modifier. The radiation modifier includes a material having a graded dielectric constant. A final portion of the radiation modifier includes material having a dielectric constant that produces a signal phase velocity in signals emitted from the radiation modifier that is substantially equal to a phase velocity of signals on the surface.

Abstract: A control interface circuitry configured to control an array element of a phased array antenna system. The control interface circuitry comprises: 1) a first RF combiner network for transceiving first RF signals with first transmit/receive path circuitry in the array element; and 2) a central controller configured to communicate with control logic circuitry in the array element, the control logic circuitry controlling operation of the first transmit/receive path circuitry. During Data mode, the central controller transfers control data to the control logic circuitry via the first RF combiner network. During RF mode, the first RF combiner network transceives the first RF signals with the first transmit/receive path circuitry. The control interface circuitry further comprises: iii) a second RF combiner network for receiving second RF signals from second receive path circuitry in the array element.

Abstract: Digital video signals are transmitted from a transmitter to a receiver via a digital video interface including shielded twisted pair cables that are surrounded by an over-braid shield. The over-braid shield is connected to a chassis ground at a transmitting end and the receiving end. An interface conveys the received signals to receiver processing circuitry. The interface is connected to an isolated ground, isolating the receiver processing circuitry. The twisted pairs are also connected to the isolated ground, such that a return current is forced back through the twisted pair cable shields rather than the over-braid shield. This reduces electromagnetic emissions and confines transients primarily to the over-braid shield.