Atomic spin gyroscope (ASG) based on comagnetometer is a high sensitive and compact gyroscope for future inertial navigation applications. The start-up time was several hours of the demonstrated ASGs based on 3He-K or21 Ne-Rb-K comagnetometer, and only a few inertial navigation applications allow such a long time for preparation. We report the demonstration of an ASG based on 129Xe-Cs comagnetometer, which decreases the start-up time to 10 minutes and decreases the operation temperature by 40% as well. By operating this ASG in spin exchange relaxation free regime, a sensitivity of 7×10 -5 °/(s Hz1/2) was achieved.
Aimed at low accuracy of attitude determination because of using low-cost components which may result in non-linearity in integrated attitude determination systems, a novel attitude determination algorithm using vector observations and gyro measurements is presented. The various features of the unscented Kalman filter （UKF） and optimal-REQUEST （quaternion estimator） algorithms are introduced for attitude determination. An interlaced filtering method is presented for the attitude determination of nano-spacecraft by setting the quaternion as the attitude representation, using the UKF and optimal-REQUEST to estimate the gyro drifts and the quaternion, respectively. The optimal-REQUEST and UKF are not isolated from each other. When the optimal-REQUEST algorithm estimates the attitude quaternion, the gyro drifts are estimated by the UKF algorithm synchronously by using the estimated attitude quaternion. Furthermore, the speed of attitude determination is improved by setting the state dimension to three. Experimental results show that the presented method has higher performance in attitude determination compared to the UKF algorithm and the traditional interlaced filtering method and can estimate the gyro drifts quickly.
