Scale factor calibration and dynamic angle measurement method based on self-collimator and fiber optic gyroscope

•The scale factor, which the output of the fiber optic gyroscope (FOG) is proportional to, is sensitive to many factors in engineering.•When the scale factor used fluctuates during the angle measurement process, it will bring an error to the angle measurement results. In this work, we analyzed the error caused by the scale factor instability of the FOG in engineering and proposed a real-time calibration scheme for the scale factor of the FOG based on self-collimator during the process of angle measurement.•Experimental results show that the angle measurement error can be kept stable and in a high precision for a long time by adopting the scheme.•Compared with other calibration or compensation methods on the scale factor, the real-time calibration method based on the self-collimator described in this paper is simpler, more feasible, and more convenient.•Also, the method doesn’t need complex calculations or make optimizations in the structure and performance of the FOG. Thus, this method is more suitable to apply in engineering and easy to realize.