Abstract: Described herein are methods of inhibiting or reversing the progression of cataract formation or presbyopia in an eye by administering a ?-crystallin charge masking agent. Both presbyopia and cataracts are caused by aggregation of the soluble crystalline lens proteins called the crystallins.

Abstract: Described herein are methods of inhibiting or reversing the progression of cataract formation or presbyopia in an eye by administering a ?-crystallin charge masking agent. Both presbyopia and cataracts are caused by aggregation of the soluble crystalline lens proteins called the crystallins.

Abstract: Described herein are methods of inhibiting or reversing the progression of cataract formation or presbyopia in an eye by administering a ?-crystallin charge masking agent. Both presbyopia and cataracts are caused by aggregation of the soluble crystalline lens proteins called the crystallins.

Abstract: Described herein are methods of inhibiting or reversing the progression of cataract formation or presbyopia in an eye by administering a ?-crystallin charge masking agent. Both presbyopia and cataracts are caused by aggregation of the soluble crystalline lens proteins called the crystallins.

Abstract: An example embodiment includes a method for initializing a navigation system. The method includes receiving inertial measurement data from an inertial measurement unit over time and storing the inertial measurement data in a buffer with an indication of a time of validity for the inertial measurement data. The method also includes receiving navigation data from an aiding source, the navigation data having a time of validity, and initializing a navigation solution with the navigation data. The method also includes summing inertial measurement data from the buffer to produce an inertial motion estimate for a time increment after the time of validity of the navigation data, applying at least one of coning or sculling compensation to the inertial motion estimate to produce a compensated inertial motion estimate, and propagating the navigation solution forward based on the compensated inertial motion estimate.

Abstract: Systems and methods for feature selection and matching are provided. In certain embodiments, a method for matching features comprises extracting a first plurality of features from current image data acquired from at least one sensor and extracting a second plurality of features from a prior map, wherein the prior map represents an environment containing the navigation system independently of data currently acquired by the at least one sensor. The method also comprises identifying at least one first feature in the first plurality of features and at least one second feature in the second plurality of features that have associated two-dimensional representations; and identifying at least one corresponding pair of features by comparing a three-dimensional representations of the at least one first feature to a three-dimensional representation of the at least one second feature.

Abstract: A method for collaborative navigation between two or more platforms is provided. The method comprises establishing a communication link between a first platform and a second platform, making a sensor measurement from the first platform, updating state and covariance elements of the first platform, and transmitting the updated state and covariance elements from the first platform to the second platform. A conditional update is performed on the second platform to compute a new estimate of state and covariance elements on the second platform, which takes into account the measurement from the first platform. The method further comprises making a sensor measurement from the second platform, updating state and covariance elements of the second platform, and transmitting the updated state and covariance elements from the second platform to the first platform.

Abstract: An inertial sensing system comprises a first multi-axis atomic inertial sensor, a second multi-axis atomic inertial sensor, and an optical multiplexer optically coupled to the first and second multi-axis atomic inertial sensors. The optical multiplexer is configured to sequentially direct light along different axes of the first and second multi-axis atomic inertial sensors. A plurality of micro-electrical-mechanical systems (MEMS) inertial sensors is in operative communication with the first and second multi-axis atomic inertial sensors. Output signals from the first and second multi-axis atomic inertial sensors aid in correcting errors produced by the MEMS inertial sensors by sequentially updating output signals from the MEMS inertial sensors.

Abstract: A method for navigation comprises constructing a current map that includes two-dimensional or three dimensional representations of an area, detecting one or more edge features on the current map, and generating a first fine-edge map based on the edge features. The method further comprises retrieving a historical map that includes two-dimensional or three dimensional representations of the area, detecting one or more edge features on the historical map, and generating a second fine-edge map based on the edge features. Thereafter, a coarse version of the current map is generated from the first fine-edge map, and a coarse version of the historical map is generated from the second fine-edge map. The coarse versions of the current and historical maps are then correlated to determine a first position and orientation. The first fine-edge map is then correlated with the second fine-edge map to determine a second, more accurate, position and orientation.

Abstract: Systems and methods for feature selection and matching are provided. In certain embodiments, a method for matching features comprises extracting a first plurality of features from current image data acquired from at least one sensor and extracting a second plurality of features from a prior map, wherein the prior map represents an environment containing the navigation system independently of data currently acquired by the at least one sensor. The method also comprises identifying at least one first feature in the first plurality of features and at least one second feature in the second plurality of features that have associated two-dimensional representations; and identifying at least one corresponding pair of features by comparing a three-dimensional representations of the at least one first feature to a three-dimensional representation of the at least one second feature.

Abstract: A method for wide baseline feature matching comprises capturing one or more images from an image sensor on each of two or more platforms when the image sensors have overlapping fields of view, performing a 2-D feature extraction on each of the captured images in each platform using local 2-D image feature descriptors, and calculating 3-D feature locations on the ellipsoid of the Earth surface from the extracted features using a position and attitude of the platform and a model of the image sensor. The 3-D feature locations are updated using digital terrain elevation data (DTED) as a constraint, and the extracted features are matched using the updated 3-D feature locations to create a common feature zone. A subset of features from the common feature zone is selected, and the subset of features is inputted into a collaborative filter in each platform. A convergence test is then performed on other subsets in the common feature zone, and falsely matched features are pruned from the common feature zone.

Abstract: A method for navigation comprises constructing a current map that includes two-dimensional or three dimensional representations of an area, detecting one or more edge features on the current map, and generating a first fine-edge map based on the edge features. The method further comprises retrieving a historical map that includes two-dimensional or three dimensional representations of the area, detecting one or more edge features on the historical map, and generating a second fine-edge map based on the edge features. Thereafter, a coarse version of the current map is generated from the first fine-edge map, and a coarse version of the historical map is generated from the second fine-edge map. The coarse versions of the current and historical maps are then correlated to determine a first position and orientation. The first fine-edge map is then correlated with the second fine-edge map to determine a second, more accurate, position and orientation.

Abstract: An inertial sensing system comprises a first multi-axis atomic inertial sensor, a second multi-axis atomic inertial sensor, and an optical multiplexer optically coupled to the first and second multi-axis atomic inertial sensors. The optical multiplexer is configured to sequentially direct light along different axes of the first and second multi-axis atomic inertial sensors. A plurality of micro-electrical-mechanical systems (MEMS) inertial sensors is in operative communication with the first and second multi-axis atomic inertial sensors. Output signals from the first and second multi-axis atomic inertial sensors aid in correcting errors produced by the MEMS inertial sensors by sequentially updating output signals from the MEMS inertial sensors.

Abstract: Systems and methods to incorporate master navigation system resets during transfer alignment are provided. In one embodiment, a system comprises: a set of local inertial sensors; a local navigation processor coupled to local inertial sensors, the local navigation processor receiving inertial navigation data from local inertial sensors and converting the data into a navigation solution; a local Kalman filter (LKF) coupled to the local navigation processor and a master Kalman filter (MKF), the LKF receiving the navigation solution. The LKF receives from the MKF a Precision Transfer Alignment Message (PTAM) that includes at least one navigation aid measurement. The LKF inputs the navigation aid measurement into a measurement formation algorithm and calculates a measurement residual. The LKF receives from the MKF a Reset Transfer Alignment Message (RTAM) that includes a bias correction. The LKF inputs the bias correction into a state propagation algorithm to add to a navigation state.

Abstract: Systems and methods to incorporate master navigation system resets during transfer alignment are provided. In one embodiment, a system comprises: a set of local inertial sensors; a local navigation processor coupled to local inertial sensors, the local navigation processor receiving inertial navigation data from local inertial sensors and converting the data into a navigation solution; a local Kalman filter (LKF) coupled to the local navigation processor and a master Kalman filter (MKF), the LKF receiving the navigation solution. The LKF receives from the MKF a Precision Transfer Alignment Message (PTAM) that includes at least one navigation aid measurement. The LKF inputs the navigation aid measurement into a measurement formation algorithm and calculates a measurement residual. The LKF receives from the MKF a Reset Transfer Alignment Message (RTAM) that includes a bias correction. The LKF inputs the bias correction into a state propagation algorithm to add to a navigation state.

Abstract: An example embodiment includes a method for initializing a navigation system. The method includes receiving inertial measurement data from an inertial measurement unit over time and storing the inertial measurement data in a buffer with an indication of a time of validity for the inertial measurement data. The method also includes receiving navigation data from an aiding source, the navigation data having a time of validity, and initializing a navigation solution with the navigation data. The method also includes summing inertial measurement data from the buffer to produce an inertial motion estimate for a time increment after the time of validity of the navigation data, applying at least one of coning or sculling compensation to the inertial motion estimate to produce a compensated inertial motion estimate, and propagating the navigation solution forward based on the compensated inertial motion estimate.

Abstract: A method for collaborative navigation between two or more platforms is provided. The method comprises establishing a communication link between a first platform and a second platform, making a sensor measurement from the first platform, updating state and covariance elements of the first platform, and transmitting the updated state and covariance elements from the first platform to the second platform. A conditional update is performed on the second platform to compute a new estimate of state and covariance elements on the second platform, which takes into account the measurement from the first platform. The method further comprises making a sensor measurement from the second platform, updating state and covariance elements of the second platform, and transmitting the updated state and covariance elements from the second platform to the first platform.

Abstract: A method for wide baseline feature matching comprises capturing one or more images from an image sensor on each of two or more platforms when the image sensors have overlapping fields of view, performing a 2-D feature extraction on each of the captured images in each platform using local 2-D image feature descriptors, and calculating 3-D feature locations on the ellipsoid of the Earth surface from the extracted features using a position and attitude of the platform and a model of the image sensor. The 3-D feature locations are updated using digital terrain elevation data (DTED) as a constraint, and the extracted features are matched using the updated 3-D feature locations to create a common feature zone. A subset of features from the common feature zone is selected, and the subset of features is inputted into a collaborative filter in each platform. A convergence test is then performed on other subsets in the common feature zone, and falsely matched features are pruned from the common feature zone.

Abstract: Methods for internally curing cement-based materials using wood-derived materials as internal curing agents are disclosed herein. The methods generally include casting a mixture of a cement-based material, mixing water, and an internal curing agent, which includes a wood-derived material, and curing the mixture. The mixture is cured using the mixing water and any water associated with the internal curing agent. The cured mixture will shrink less than if the mixture did not include the wood-derived material. Internally cured cement-based mixtures are also described.