Abstract: Nyquist folding receivers (NYFRs) are disclosed that use three or more non-modulated sampling clock signals with different frequencies to produce multiple projections in a sampled output. Using these three or more different sampling clock signals, multiple Nyquist zones are aliased together while still allowing signals from different Nyquist zones to be separated and identified in later processing based upon the sampling provided by the different sampling clock signals. NYFR sampling receivers are also disclosed that simultaneously produce multiple separate and different parallel channels from an input signal, with each different channel having a different sampling clock sampling rate from the other channels so as to generate a respective folding pattern that is different from the folding pattern generated by the respective RF sampling rate of each of the other simultaneous and parallel channels.

Abstract: A mainlobe detection process can include a number of tests that are performed to define when the monopulse antenna system will transition from open loop scanning to closed loop scanning and then to tracking. A hybrid tracking technique is also provided which adaptively discovers and corrects for phase alignment error. Magnitude-only tracking can be performed initially to locate the nulls in the azimuth and elevation ratios and to identify the magnitudes of these ratios at these nulls. Phase tracking can be then performed. During phase tracking, phase corrections can be repeatedly applied to the azimuth and elevation difference channels to correct any phase error that may exist. During this process, the magnitudes of the ratios can be used to determine how the phase corrections should be adjusted. Once the hybrid tracking process is complete, the monopulse antenna system is properly phase-aligned and phase tracking will be correctly employed.

Abstract: Methods and systems are disclosed to operate an aircraft with modified (e.g., improved) flight performance characteristics, such as increased or maximized aircraft takeoff weight and/or longer allowable mission time for the aircraft. In one example, the aircraft may be enabled to operate with increased aircraft engine performance (e.g., such as engine power) without increasing engine temperature above the maximum allowable operating temperature limits for the engine. In a further example, available engine power may be determined during a pre-flight sequence, and utilized by an aircraft without exceeding published or manufacturer specified engine temperature limits.

Abstract: Embodiments include different multi-port ring combiners which are configured to act as multi-output signal routers. One type of multi-port ring combiner includes input ports that are driven by pairs of outphasing signals. The multi-port ring combiner also includes multiple channels that are independently routed to a first output, to a second output, or to a third output, according to a phase relationship of the multi-port ring combiner. The multi-port ring combiner enables an outphasing signal combination which provides output port selection. The multi-port ring combiner may be a 4-port ring combiner, a 5-port ring combiner or a 6-port ring combiner.

Abstract: A mainlobe detection process can include a number of tests that are performed to define when the monopulse antenna system will transition from open loop scanning to closed loop scanning and then to tracking. A hybrid tracking technique is also provided which adaptively discovers and corrects for phase alignment error. Magnitude-only tracking can be performed initially to locate the nulls in the azimuth and elevation ratios and to identify the magnitudes of these ratios at these nulls. Phase tracking can be then performed. During phase tracking, phase corrections can be repeatedly applied to the azimuth and elevation difference channels to correct any phase error that may exist. During this process, the magnitudes of the ratios can be used to determine how the phase corrections should be adjusted. Once the hybrid tracking process is complete, the monopulse antenna system is properly phase-aligned and phase tracking will be correctly employed.

Abstract: A monopulse antenna system can include a monopulse detector assembly (MDA) that is configured to steer a monopulse antenna based on the magnitude of an elevation ratio or azimuth ratio independently of the phase of the ratio. To prevent the direction of the monopulse antenna from being changed too frequently, the MDA can employ ratio bins to determine when the direction of the monopulse antenna should be reversed. Also, the MDA may enforce a hold period during which a change in the direction of the monopulse antenna will not be performed. The MDA can employ one or more mapping equations to generate a steering signal as a function of the magnitude of the ratio. The mapping equations can be selectively employed based on whether tracking is being performed at or near the ratio null.

Abstract: A monopulse tracker includes multiple dual-axis monopulse antenna systems that are angled with respect to one another. The orientations of the monopulse antenna systems create a much larger field of view for the monopulse tracker to eliminate the need to steer the monopulse tracker. The monopulse tracker can be configured to estimate a position of an object based on tracking information received from more than one monopulse antenna system therefore increasing the accuracy of the estimated position. The multiple monopulse antenna systems can be arranged in a low-profile housing to facilitate use of the monopulse tracker on aircraft.

Abstract: A battery-powered system comprising: 1) a housing adapted to contain electro-mechanical machines; and 2) an apparatus disposed within the housing. The apparatus comprises: i) a battery configured as an annular cylinder having an inner diameter, an outer diameter, and a length; and ii) a cylindrical device disposed within a cavity formed by the annular cylinder of the battery. An outer diameter of the cylindrical device is substantially the same as the inner diameter of the battery and the cylindrical device has a length substantially equal to the length of the battery. The cylindrical device may be a fluid reservoir or a second battery.

Abstract: A fusion night vision system has a plurality of hinged joints that allow an operator to adjust the distance between the left eye piece and the right eyepiece while allowing a row of pixels from a display to be maintained viewable through the right eye piece parallel with an imaginary line formed by an optical axis of the left eye piece with an optical axis of the right eye piece.

Abstract: Systems, methods, and non-transitory computer-readable media taught herein process a subset of a three-dimensional array of voxels to form an image of a region of interest in an object. Images thus formed are clear, comprehensible, and contextual. The systems, methods, and non-transitory computer-readable media taught herein select the subset of voxels that represent the region of interest along a direction perpendicular to a view direction defined by the region of interest. The subset of voxels represents one or more portions of a plurality of image slices of the object.

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: 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 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: 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.