Precision Orbit Determination And Accuracy Analysis Of Low Orbit Satellites Of GNSS On Spaceborne

With the continuous development of satellite technology,the application of low orbit satellites is becoming more and more widespread.Therefore,improving the orbit accuracy of low orbit satellites has become an important task.GNSS technology is the most commonly used means of all orbit determination all low orbit satellites,and the decisive factor affecting the orbit determination accuracy of GNSS technology is the quality of GNSS data received by the spaceborne GNSS receiver carried by low orbit satellites.This thesis focuses on the quality control of spaceborne GNSS data,develops a quality analysis software for spaceborne GNSS data,improves the traditional Turbo Edit cycle slip detection method,and analyzes the differences between kinematic orbits and reduced-dynamic orbits.The specific content of this article is as follows:(1)We have independently developed a software for analyzing the quality of spaceborne GNSS data,which can analyze the quality of spaceborne GNSS observation data.The experiment selected GRACE-FO series satellites,SWARM series satellites,and FY-3C satellites to analyze the quality of spaceborne GNSS satellite observation data from indicators such as satellite visibility,data integrity,satellite DOP value,multipath error,signal-to-noise ratio,and ionospheric delay change rate.The changes in some indicators were statistically analyzed from the satellite altitude angle level.(2)Due to the special spatial characteristics and motion status of low orbit satellites,the original Turbo Edit method has poor applicability in detecting cycle slips in spaceborne GNSS data at low altitude angles.In response to this issue,the article proposes a combination of CEEMD denoising improvement MW combination and second-order ionospheric residual elimination combination to improve the original Turbo Edit method.(3)In order to analyze the impact of different orbit determination methods on the orbit accuracy of LEO satellites,the kinematics orbits and simplified dynamic orbits of GRACE-FO C and GRACE-FO D satellites were calculated by using BERNESE5.2 software in the experiment.The internal and external coincidence accuracy of the two types of orbits were analyzed,and the impact of satellite attitude files on the simplified dynamic orbits was further evaluated.(4)The distribution and quality of the SLR data of GRACE-FO C and GRACE-FO D satellites were analyzed for simplified dynamic orbits.The relationship between SLR data and observation satellite altitude and azimuth angles was analyzed,and the accuracy of the simplified dynamic orbits of GRACE-FO satellites was verified using satellite laser ranging technology.