Abstract: Techniques are disclosed for improving daylight performance of a star tracker. A region of interest (ROI) within a field of view of sky is obtained. The region of interest is divided into sub-ROIs. Sub-ROIs including a candidate celestial object are identified. An angular velocity of each candidate celestial object is determined. The known celestial object is a candidate celestial object identified as having a angular velocity, during a time period, that is within a range of angular velocities about a known angular velocity associated with the known celestial object.

Abstract: A method and system for celestial navigation are provided. The method comprises requesting access to a light source on a low earth orbit (LEO) satellite; and sending an uplink message to the LEO satellite to power on the light source, in response to the access request. The method further comprises determining whether the LEO satellite is in view of a camera; capturing a light image, from the light source, on a focal plane location of the camera when the LEO satellite is in view of the camera; and comparing the focal plane location to a predicted location of the LEO satellite. The method updates position information of a user based on an observation error from comparing the focal plane location to the predicted location.

Abstract: A method of assuring integrity of range measurements and position solutions comprises obtaining range measurement statistics between network nodes, performing a snapshot integrity test for the range measurement statistics, and performing a sequential integrity test using the range measurement statistics. The snapshot integrity test comprises using Gram matrices with a current configuration of the nodes; performing a singular value consistency check using the Gram matrices against a user selected threshold; and detecting and excluding range measurement statistics with instantaneous errors that cause the singular value to exceed the threshold.

Abstract: A method of assuring integrity of range measurements and position solutions comprises obtaining range measurement statistics between nodes in a network, performing a snapshot integrity test for the range measurement statistics, and performing a sequential integrity test using the range measurement statistics. The snapshot integrity test comprises using Gram matrices along with a current configuration of the nodes; performing a singular value consistency check using the Gram matrices against a user selected threshold; and detecting/excluding range measurement statistics with instantaneous errors that cause the singular value to exceed the threshold.

Abstract: An example pointing system includes a sensor that measures change in angular position, a first GNSS antenna, and a second GNSS antenna mounted to a rigid body that is removable from the pointing system after calibration of the sensor. The GNSS antennas have a fixed, known baseline. The pointing system includes at least one GNSS receiver with first and second RF inputs respectively coupled to the GNSS antennas. The at least one GNSS receiver includes respective paths to process GNSS signals received from the first and second RF inputs. The pointing system includes at least one processor, communicatively coupled to the sensor and receiver, configured to: determine initial attitude of the pointing system based on the processed GNSS signals; calibrate the sensor using the determined initial attitude; determine a pointing solution for the pointing system based on measurements from the calibrated sensor without GNSS signals from second GNSS antenna.

Abstract: An example pointing system includes a sensor that measures change in angular position, a first GNSS antenna, and a second GNSS antenna mounted to a rigid body that is removable from the pointing system after calibration of the sensor. The GNSS antennas have a fixed, known baseline. The pointing system includes at least one GNSS receiver with first and second RF inputs respectively coupled to the GNSS antennas. The at least one GNSS receiver includes respective paths to process GNSS signals received from the first and second RF inputs. The pointing system includes at least one processor, communicatively coupled to the sensor and receiver, configured to: determine initial attitude of the pointing system based on the processed GNSS signals; calibrate the sensor using the determined initial attitude; determine a pointing solution for the pointing system based on measurements from the calibrated sensor without GNSS signals from second GNSS antenna.

Abstract: An Inertial Navigation System (INS) testing system includes a Unit Under Test (UUT) with an INS module, a DAT tool configured to provide command and control functions to a user, and a Dynamically Integrated Navigation Tester (DINT) in communication with the UUT and the DAT tool. The DINT includes a truth data conversion module configured to receive truth data and convert it to navigation data suitable for transmission to the UUT. The INS testing system advantageously allow a user to interface with a UUT while providing user-specified dynamic inputs from the DINT with the truth data selected by the user.

Abstract: An Inertial Navigation System (INS) testing system includes a Unit Under Test (UUT) with an INS module, a DAT tool configured to provide command and control functions to a user, and a Dynamically Integrated Navigation Tester (DINT) in communication with the UUT and the DAT tool. The DINT includes a truth data conversion module configured to receive truth data and convert it to navigation data suitable for transmission to the UUT. The INS testing system advantageously allow a user to interface with a UUT while providing user-specified dynamic inputs from the DINT with the truth data selected by the user.

Abstract: A multiple processor architecture with flexible external input/output interface is provided.

Abstract: A multiple processor architecture with flexible external input/output interface is provided.

Abstract: Relatively low VOC hair styling compositions which provide good style retention without unacceptable stickiness or stiffness are disclosed. The compositions comprise from about 0.01% to about 20%, by weight of the composition, of a hair styling polymer; and a carrier comprising at least about 0.5% to about 99.9%, by weight of the composition, of a first solvent selected from the group consisting of water; water soluble organic solvents; organic solvents which are strongly to moderately strong in hydrogen bonding parameter; and mixtures thereof; wherein the first solvent is other than C1-C3 monohydric alcohol, C1-C3 ketone, and C1-C3 ether; and from about 0% to about 55%, by weight of the composition, of a second solvent selected from the group consisting of C1-C3 monohydric alcohols, C1-C3 ketones, C1-C3 ethers, and mixtures thereof; wherein the composition is characterized by having a Stiffness Value (SV) and a Curl Retention Index (CRI), wherein SV.gtoreq.[(0.703.times.CRI)-0.425)].