Influence of Gyroscopes on the Accuracy of a Nanosatellite Attitude Estimation

In order to obtain three-axis attitude information of a nanosatellite, at least two reference directions are needed. Magnetometers and Sun sensors are the most commonly used attitude sensors for measuring these reference directions because they are inexpensive and reliable and require low power consumption. On the other hand, the use of gyroscopes for attitude determination is optional, and having an angular velocity vector measurement may increase the accuracy of the attitude estimation system. This study discusses and compares the performance of a nanosatellite attitude estimation system with and without gyroscope measurements. A nontraditional approach is used for the estimation process where a Sun direction-Earth’s magnetic field-based TRIAD algorithm and an extended Kalman filter (EKF) are integrated to reduce the computational load. Proposed attitude estimation system is simulated with and without gyroscope measurements, and their estimation accuracies are compared. As a result of simulations, it is seen that the use of gyroscopes improves the attitude estimation accuracy by up to 16%.