High Precision Star Tracker with Dynamic Post-Calibration Framework

Star trackers represent a crucial element in celestial navigation and tracking, with applications in astronomy or aerospace activities. The paper describes a cost-effective star tracker system to track celestial objects with respect to the equatorial coordinate system. The system uses floating-point values of right ascension and declination to determine the target object's position, whereas user-provided latitude and longitude are used for the calibration with Local Sidereal Time through the Julian date calculations. A notable feature of the system is its auto-tracking capability, which can automatically and continuously track a celestial object once aligned. To address errors unique to the measurements of the gyroscopic measurements, the system has built-in correction mechanisms that adjust errors from pitch and yaw dynamically for precise alignment to the targeted celestial object. Sensor fusion enhances orientation accuracy through an integration of accelerometer and gyroscope data using an integrated complementary filter to eliminate noise and drift. Through experimental validation, the proposed system is shown to be capable of an accurate tracking process in diverse conditions, restricting angular deviation within acceptable limits. This easy-to-construct and cost-effective design thus provides a solid platform for amateur astronomy, educational and research purposes.