Abstract: Systems and methods for operating a navigation system and detecting GNSS spoofing using a chip-scale atomic clock are provided herein.

Abstract: Systems and methods for operating a navigation system and detecting GNSS spoofing using a chip-scale atomic clock are provided herein.

Abstract: A system comprises a GNSS receiver that receives a GNSS signal and produces GNSS measurements; a plurality of inertial sensors that produce inertial data; and a navigation system comprising a Kalman filter and an inertial navigation unit. The Kalman filter receives the GNSS measurements and calculates pseudo-range residuals, delta-range residuals, pseudo-range chi square values, delta-range chi square values, accelerometer bias estimates, and gyroscope bias estimates. A spoof detection system communicates with the Kalman filter and comprises a set of detection monitors that determine an integrity of the GNSS measurements. The detection monitors detect if the pseudo-range residuals, the delta-range residuals, the pseudo-range chi-square values, the delta-range chi-square values, the accelerometer bias estimates, or the gyroscope bias estimates, go beyond a fail threshold indicating that the GNSS signal is abnormal.

Abstract: Systems and methods for operating a navigation system and detecting GNSS spoofing using a chip-scale atomic clock are provided herein.

Abstract: Systems and methods for operating a navigation system and detecting GNSS spoofing using a chip-scale atomic clock are provided herein.

Abstract: A ring laser gyroscope comprises a block defining a hermetically sealed cavity for a ring laser formed when a lasing medium disposed within the cavity is excited. A cathode and an anode are attached to the block at two fill positions comprised within the cavity, and exposed to the lasing medium such that the lasing medium is ionized when a high voltage pulse is supplied across cathode and anode. At least two RF electrodes are attached to the block, positioned on opposing sides to generate a capacitive discharge for the purpose of keeping the lasing medium excited. The gyro comprises a matching circuit to tune the frequency of a radio frequency (RF) signal generated by a RF power source before the RF signal is sent to the electrodes. The matching circuit is coupled to the RF electrodes via respective lead wires, and comprises an element matching network.

Abstract: A method of magnetic sensor calibration for aircraft comprises obtaining attitude data, heading angle data, position data, and date information; inputting the position data and date into an earth magnetic field (EMF) model and into an EMF model correction map; inputting the attitude and heading angle data into a NOLL to body frame transformation module; outputting an EMF model vector from the EMF model; outputting an EMF correction vector from the EMF model correction map; compensating the EMF model vector with the EMF correction vector to produce a corrected EMF model vector; inputting the corrected EMF model vector into the transformation module; inputting magnetic field measurements data into a calibration processing unit; inputting true earth magnetic field data from the transformation module into the processing unit; computing compensation coefficients in the processing unit based on the magnetic field measurements and the true earth magnetic field; and storing the compensation coefficients.

Abstract: A ring laser gyroscope comprises a block defining a hermetically sealed cavity for a ring laser formed when a lasing medium disposed within the cavity is excited. A cathode and an anode are attached to the block at two fill positions comprised within the cavity, and exposed to the lasing medium such that the lasing medium is ionized when a high voltage pulse is supplied across cathode and anode. At least two RF electrodes are attached to the block, positioned on opposing sides to generate a capacitive discharge for the purpose of keeping the lasing medium excited. The gyro comprises a matching circuit to tune the frequency of a radio frequency (RF) signal generated by a RF power source before the RF signal is sent to the electrodes. The matching circuit is coupled to the RF electrodes via respective lead wires, and comprises an element matching network.

Abstract: A method of magnetic sensor calibration for aircraft comprises obtaining attitude data, heading angle data, position data, and date information; inputting the position data and date into an earth magnetic field (EMF) model and into an EMF model correction map; inputting the attitude and heading angle data into a NOLL to body frame transformation module; outputting an EMF model vector from the EMF model; outputting an EMF correction vector from the EMF model correction map; compensating the EMF model vector with the EMF correction vector to produce a corrected EMF model vector; inputting the corrected EMF model vector into the transformation module; inputting magnetic field measurements data into a calibration processing unit; inputting true earth magnetic field data from the transformation module into the processing unit; computing compensation coefficients in the processing unit based on the magnetic field measurements and the true earth magnetic field; and storing the compensation coefficients.

Abstract: A system comprises an inertial measurement unit comprising one or more gyroscopes configured to measure angular velocity about a respective one of three independent axes and one or more accelerometers configured to measure specific force along a respective one of the three independent axes; a magnetometer configured to measure strength of a local magnetic field along each of the three independent axes; and a processing device coupled to the inertial measurement unit and the magnetometer; the processing device configured to compute kinematic state data for the system based on measurements received from the magnetometer and the inertial measurement unit. The processing device is further configured to calculate magnetometer measurement calibration parameters using a first technique when position data is unavailable and to calculate magnetometer measurement calibration parameters using a second technique when position data is available.