摘要
实时导航定位中需要利用广播星历实时计算卫星位置,日本建设的准天顶卫星系统(QZSS)计算卫星位置时通过不断迭代提高计算精度,导致实时解算效率降低.为了保证QZSS广播星历坐标计算精度且提高运算效率,提出利用切比雪夫多项式拟合卫星轨道.首先,使用原有方法计算卫星位置,以精密星历为参考,验证QZSS广播星历的卫星坐标精度为米级;然后,针对卫星三维(3D)坐标使用切比雪夫多项式进行拟合,并讨论影响拟合精度的因素,在拟合时间间隔固定时,最优拟合阶数随节点个数增多而增大;不同时间间隔下,不同轨道类型的最优拟合阶数不相等,同一轨道最优拟合阶数相等,但随时间间隔的增大拟合误差也逐渐增大.结果表明:使用切比雪夫多项式拟合QZSS广播星历时,针对不同的轨道类型选择合适的拟合时间间隔和拟合阶数,其拟合精度和运算效率均可满足需要.
Broadcast ephemeris is needed to calculate the satellite position in real-time navigation and positioning.The continuous iteration is used to improve the calculation accuracy in the quasi-zenitic satellite system(QZSS)built by Japan during calculating the satellite position,which can result in the real-time calculation efficiency reduction.In order to ensure the calculation accuracy and improve the calculation efficiency of QZSS broadcast ephemeris coordinates,a chebyshev polynomial is proposed to fit the satellite orbit.Firstly,the traditional methods are used to calculate satellite position,the precision ephemeris is regarded as a reference to verify that the satellite coordinate accuracy of QZSS broadcast ephemeris is meter-level.And then,a chebyshev polynomial is used to fit satellite three-dimension coordinates,and the factors affecting the fitting accuracy are discussed.When the fitting time-interval is fixed,the optimal fitting order increases with the number of nodes;Under different time-intervals,the optimal fitting order is not equal in different orbit types,and the optimal fitting order of the same orbit is equal,but the fitting error gradually increases with the increase of time-interval.The result shows that QZSS broadcast ephemeris can be fitted by using a chebyshev polynomial and choosing appropriate fitting time-interval and fitting order for different orbit types.The fitting accuracy and computational efficiency can meet the needs.
作者
寇瑞雄
杨树文
KOU Ruixiong;YANG Shuwen(College of Surveying and GEO-Informatics,Lanzhou Jiaotong University,Lanzhou 730070,China;National-Local Joint Engineering Research Center of Technologies and Applications for National Geographic State Monitoring,Lanzhou 730070,China;Gansu Provincial Engineering Laboratory for National Geographic State Monitoring,Lanzhou 730070,China)
出处
《全球定位系统》
CSCD
2021年第5期39-47,共9页
Gnss World of China
基金
国家重点研发计划项目(2017YFB0504201)
国家自然科学基金项目(41761082)
甘肃省教育厅:优秀研究生“创新之星”项目(2021CXZX-546)
兰州交通大学优秀平台支持项目(201806)。