Abstract: Designs and processes for thermally stabilizing a vertical cavity surface emitting laser (vcsel) in a chip-scale atomic clock are provided. In one embodiment, a Chip-Scale Atomic Clock includes: a vertical cavity surface emitting laser (vcsel); a heater block coupled to a base of the vcsel; a photo detector; a vapor cell, wherein the vapor cell includes a chamber that defines at least part of an optical path for laser light between the vcsel and the photo detector; and an iso-thermal cage surrounding the vcsel on all sides, the iso-thermal cage coupled to the heater block via a thermally conductive path.

Abstract: A memory array comprises a plurality of memory cells organized in a matrix of rows and columns. Each of the memory cells includes a high voltage access transistor, a floating gate memory transistor electrically connected to the access transistor, and a coupling capacitor electrically connected to the memory transistor. A first set of word lines are each electrically connected to the capacitor in each of the memory cells in a respective row. A second set of word lines are each electrically connected to the access transistor in each of the memory cells in a respective row. A first set of bit lines are each electrically connected to the access transistor in each of the memory cells in a respective column. A second set of bit lines are each electrically connected to the memory transistor in each of the memory cells in a respective column.

Abstract: Systems and methods for IP communication over a distributed antenna system transport are provided. In one embodiment, a method for providing Ethernet connectivity over a distributed antenna system comprises receiving internet protocol (IP) formatted data from an internet protocol device coupled to a remote unit of a distributed antenna system; sampling wireless radio frequency (RF) signals received at the remote unit to produce digitized RF samples; generating a serial data stream for output to a host unit of the distributed antenna system, the serial data stream further comprising a multiple-timeslot communication frame providing a first partition of bandwidth for transporting the digitized RF samples and a second partition of bandwidth for implementing an Ethernet pipe for transporting the IP formatted data.

Abstract: Systems and methods for a retractable fan cooling system for an electronics enclosure are provided. In one embodiment, a system comprises at least one cooling fan coupled to an electronics enclosure having a heat sink; and a fan positioning mechanism coupled to the at least one cooling fan. When a temperature inside the electronics enclosure is less than a first temperature, the positioning mechanism places the at least one cooling fan into a retracted position that does not inhibit a natural convective air flow across the heat sink. When the temperature inside the enclosure is greater than a second temperature, the positioning mechanism places the at least one cooling fan into an engaged position that produces a forced air flow across the heat sink.

Abstract: A RFOG comprises a reference laser configured to produce a reference laser beam; a first laser source configured to produce a first laser beam; a second laser source configured to produce a second laser beam; a sensing resonator coupled to the first and second laser sources such that the first and second laser beams propagate through the sensing resonator in first and second directions, respectively; resonance tracking electronics configured to generate first and second control signals that indicate when the first and second laser beams, respectively, are off resonance; first and second optical combiners configured to beat the first and second outputs of the sensing resonator with the reference laser beam creating first and second beat signals, respectively; wherein the resonance tracking electronics is configured to discriminate between at least one rotation-sensing error and the first and second outputs of the resonator based on the first and second beat signals.

Abstract: A method for real-time visual odometry comprises capturing a first three-dimensional image of a location at a first time, capturing a second three-dimensional image of the location at a second time that is later than the first time, and extracting one or more features and their descriptors from each of the first and second three-dimensional images. One or more features from the first three-dimensional image are then matched with one or more features from the second three-dimensional image. The method further comprises determining changes in rotation and translation between the first and second three-dimensional images from the first time to the second time using a random sample consensus (RANSAC) process and a unique iterative refinement technique.

Abstract: Systems and methods for fiber-optic gyroscopes are provided. In one embodiment, a fiber-optic gyroscope comprises: a light source current servo coupled to a light source that transmits light through an optic path, wherein the light source current servo controls intensity of light through the optic path via a light source current drive that supplies current to power the light source; and an intensity control signal processor coupled to the optic path via a photo detector, wherein the intensity control signal processor outputs an intensity control signal to the light source current servo, wherein the intensity control signal is a function of intensity of light as received at the photo detector; wherein the light source current servo compares the intensity control signal against a stable analog voltage reference to adjust the light source current drive and drive optical power at the photo detector towards a constant level.

Abstract: An inertial navigation system includes a housing mountable to a vehicle and a sensor assembly located within the housing. The sensor assembly includes at least one accelerometer or gyroscope operable to measure an amount of movement of the sensor assembly. In addition, at least one adjustable mount attaches the sensor assembly to the housing and is adjustable to change its stiffness, and thus its natural frequency, based on a signal initially generated by the sensor assembly, processed by a processor, and then received through a feedback control loop. In one embodiment, the adjustable mount may take the form of a piezoelectric device. In another embodiment, the adjustable mount may take the form of a magnetorheological fluid device.

Abstract: A communication system comprises a first unit; and a second unit communicatively coupled to the first unit. The first unit is operable to receive a first original radio frequency signal via a first interface and the second unit is operable to receive a second original radio frequency signal via a second interface. The second unit is operable to output a first reproduced radio frequency signal via the second interface, the first reproduced radio frequency signal being derived from the first original radio frequency signal. The first unit is operable to output a second reproduced radio frequency signal via one of the first interface and a third interface, the second reproduced radio frequency signal being derived from the second original radio frequency signal. The first interface is operable as a simplex interface when the second reproduced radio frequency signal is output via the third interface and as a duplex interface when the second reproduced radio frequency signal is output via the first interface.

Abstract: A broadband light source configured to emit a stable broadband optical beam is provided. The broadband light source includes at least one optical pump source, an optical system including a polarization beam combiner, and a solid state laser medium. The optical system is configured to receive at least one optical pump beam from a respective one of the at least one optical pump source. The solid state laser medium receives a substantially unpolarized pump beam from a first output of the optical system. Stable broadband amplified spontaneous emission is output from a second output of the optical system.

Abstract: A method for displaying data in an avionics communications system is disclosed. The method generates an ARINC 661 definition file and a user database from one or more user-defined inputs for a communications management function of an aircraft. To convey information relating the one or more user-defined inputs with at least one display of the aircraft, the method links one or more display attributes of the user database with the ARINC 661 definition file. Based on user interactions with the at least one display, the method updates display data of the at least one display using the contents of the ARINC 661 definition file and the user database.

Abstract: A method of providing position estimation with a navigation device comprises periodically recording magnetic field strength of an area substantially surrounding a navigation device as a user of the navigation device traverses a select pathway. The method combines the recorded magnetic field strength with measurements from at least a dead reckoning portion of the navigation device to provide position estimates along the select pathway. The method further corrects each of the position estimates from a starting position on the select pathway, where each of the corrected position estimates have an error value below one or more previous position estimates and any intervening positions between each of the one or more previous position estimates and the starting position, with the error value corresponding to an error threshold based on the previous position estimates.

Abstract: A method and system for navigation quality estimation is provided. The method comprises obtaining an alignment observation, comparing the alignment observation to a current heading estimate, and updating the current heading estimate based on the comparison. A heading error estimate is updated based on the updated current heading estimate, and an estimated drift rate is determined based on the heading error estimate and an operational latitude. A determination is then made whether a drift rate requirement is met by the estimated drift rate. If the drift rate requirement is not met, the method is repeated until the drift rate requirement is met.

Abstract: Systems and methods for point-to-multipoint communications with CAS are provided. In one embodiment, a method for providing CAS for a point-to-multipoint communication network comprises: providing a network having a first network interface adapted to communicate with a first fractional network interface and a second fractional network interface; mapping a first set of user-data timeslots of the first network interface to timeslots of the first fractional network interface and mapping a second set of user-data timeslots of the first network interface to timeslots of the second fractional network interface, the first set including a first N user-data timeslots and the second set including a next M user-data timeslots; mapping a first set of signaling bits associated with the first set of user-data timeslots with the first fractional network interface; and mapping a second set of signaling bits associated with the second set of user-data timeslots with the second fractional network interface.

Abstract: A tester is configured to access and test each redundant channel of a voter. The tester is disposed between the voter and a multitude of redundant circuits supplying redundant channel signals to the voter. The tester includes a number of input ports receiving the redundant channel signals as well as the test signals. In response to a number of logic combinations of the test signals, the voter generates output signals each corresponding to one of the redundant channel signals. In response to other logic combinations of the test signals, the voter generates a voted output signal. The voter is optionally a majority voter.

Abstract: A special node is used in a distributed time-triggered cluster. The special node comprises protocol functionality to establish a time base to use in communicating with a plurality of end nodes and to source timing-related frames to the plurality of end nodes in accordance with the distributed time-triggered communication protocol. The protocol functionality establishes the time base without regard to any timing-related frame sourced from any of the plurality of end nodes. In one embodiment, the protocol functionality of the special node is implemented in a low complexity manner. In one embodiment, the cluster comprises a star topology and the special node performs at least one of semantic filtering and rate enforcement. In another embodiment, the cluster comprises a bus or peer-to-peer topology and each end node is coupled to the communication channel using a low-complexity special local bus guardian.

Abstract: A method for automatically adapting to statically varying packet sizes at a transmission convergence layer is provided. The method includes determining if an output of calculation logic in boundary detection circuitry is equal to a next value in a data stream being received, providing output indicative of an identified packet boundary to a synchronization circuit and a packet size calculator when the output equals the next value, determining a size of a packet at the packet size calculator based on two consecutive packet boundaries identified by the boundary detection circuitry, receiving output from the boundary detection circuitry and the packet size calculator at the synchronization circuit; and one of entering, remaining, or exiting a synchronous state. The entering the synchronous state is based on a counting of consecutive good packet boundaries. The exiting the synchronous state is based on a counting of consecutive missed boundaries.

Abstract: An aircraft inertial system comprises at least two inertial reference units (IRU) that provide a first set of inertial signal data for an aircraft and at least two attitude heading reference systems (AHRS) that provide a second set of the inertial signal data for the aircraft. At least one primary flight display receives the first and the second sets of the inertial signal data, and a standby flight display receives at least the second set of the inertial signal data from at least one of the AHRS. When a single fault condition occurs, the primary flight display continues to operate with fail-operational redundancy from at least three independent sources of the inertial signal data comprising one or more IRU and AHRS combinations. The standby flight display will operate using a different source of the inertial signal data than the source of the inertial signal data for the primary flight display.

Abstract: In one embodiment, a method for distributed power control in a network is provided. The method determines a transmit power for a plurality of transmitting nodes such that signals sent from each of the transmitting nodes are received at a receiving node at a signal to interference plus noise ratio (SINR) set point. Additionally, the method increases the SINR at the receiving node of one or more transmitting nodes of the plurality of transmitting nodes, and decreases the SINR at the receiving node of one or more other transmitting nodes of the plurality of transmitting nodes; wherein a total increase in SINR by the one or more transmitting nodes is substantially equal to total decrease in SINR by the one or more other transmitting nodes.

Abstract: A method of extracting a feature from a point cloud comprises receiving a three-dimensional (3-D) point cloud representing objects in a scene, the 3-D point cloud containing a plurality of data points; generating a plurality of hypothetical features based on data points in the 3-D point cloud, wherein the data points corresponding to each hypothetical feature are inlier data points for the respective hypothetical feature; and selecting the hypothetical feature having the most inlier data points as representative of an object in the scene.