Error Correction Of Fiber Optic Gyroscope Measurement Data And Universal Time Solution

Universal Time(UT)is a time measurement system based on Earth’s rotation,and it is also the core component of Time in Taiwan system.It has important application value in the fields of national defense science and technology,aerospace,high-precision time service,precision measurement,satellite navigation,space exploration,surface science and Seismology.At present,China mainly relies on the data provided by the International Earth’s rotation and Reference System Service(IERS).Compared with the current methods for measuring UT1 parameters,the measurement of Universal Time based on Fibre-optic gyroscope has the advantages of high real-time and high resolution,which has attracted attention in recent years.At present,the National Time Service Center of the Chinese Academy of Sciences has established a measurement system based on Fibre-optic gyroscope,and established a scientific and technological system for autonomous measurement and calculation of UT1 parameters,which is mainly used to monitor the earth’s rotation angle speed.However,in the actual measurement process,because the Fibre-optic gyroscope observation platform is directly connected to the earth’s surface,the measurement process will be affected by the geological activities and physical environment of the region,As a result,Universal Time UT1 is difficult to measure accurately and predict accurately for a long time.Therefore,based on the Fibre-optic gyroscope’s measurement of the earth’s angular velocity,this paper makes a preliminary analysis of the structure and operation mechanism of the system,and based on the original data of the Fibre-optic gyroscope’s measurement of the earth’s instantaneous angular velocity,studies the error sources of the original measurement data,establishes the corresponding error model and corrects the errors in the measurement,and initially completes the Universal Time UT1 calculation.The main research content is as follows:(1)Based on the measurement principle of the fiber optic gyroscope,the relationship between the angular velocity and the phase difference of the output of the fiber optic gyroscope is obtained.Combined with the conversion relationship between the earth coordinate systems,a reference frame that can directly measure the angular velocity of the earth on the surface of the earth is established,and the corresponding observation equation is established.Finally,combined with the observation equation,the universal time solution processing block diagram is constructed.(2)In the process of monitoring the earth rotation,the position of the axis of rotation of the earth in the earth coordinate system changes in real time.This change is called polar motion,which will cause the phase difference of the output of the fiber optic gyroscope to change during the measurement process.Therefore,it is necessary to establish a pole shift correction model to correct the phase difference introduced into the axis of rotation.The uneven Mass distribution of the Earth will be affected by the gravity of the sun,moon and other planets,which will also lead to the real-time change of the Earth’s axis of rotation in the inertial space.Therefore,it is necessary to establish precession and nutation models for correction.By introducing pole shift and precession nutation models,the measurement data of fiber optic gyroscopes can be corrected.(3)In addition to errors caused by geophysical factors,the environment in which the measurement system is located can also easily lead to fiber optic gyroscopes being unable to accurately measure the Earth’s rotational velocity,such as temperature,air pressure,humidity,etc.Therefore,this article proposes an improved self calibration regression calibration method based on the direct calibration method.By continuously correcting the initial calibration value,the drift of the fiber optic gyroscope can be detected in real-time and dynamically,enabling the fiber optic gyroscope to not only eliminate instrument environmental noise during the calculation process,but also operate stably for a long time.(4)For the solution of universal time UT1,the relationship between the earth’s angular velocity and universal time UT1 is established through the existing theory,and the feasibility of solving UT1 parameters is confirmed by using the measured angular velocity data of fiber optic gyroscope.Finally,the paper uses the measured data for error correction and universal time UT1 calculation,and finally uses the measured data to compare with the UT1 parameters provided by IERS,The feasibility of using fiber optic gyroscope to measure universal time is verified.