地球定向参数对天文定位定向的影响分析

Influence of Earth Orientation Parameter on Celestial Fix and Astronomical Orientation

在天文定位定向中需要用到地球定向参数的预报值,实现地心地固坐标系和地心惯性坐标系之间的相互转换,但在实时解算时,无法获得最新的地球定向参数值,研究地球定向参数预报误差将有助于提高天文解算精度。介绍了天文定位定向原理,对地球定向参数在其中的应用进行了研究,并分别分析了地球定向参数短期和长期预报值的精度,以及参数预报误差对天文定位定向的影响。结果表明,一等天文测量中纬度和方位角的解算可采用365d地球定向参数预报值,经度的解算需要进行每季度预报数据的更新。以上结论在天文导航和天文测量中有较好的借鉴意义。

The prediction of earth orientation parameters（EOP）can be used in the celestial fix and astronomical orientation,it can achieve the translation of conventional terrestial system and geocentric celestial reference system,but the latest EOP parameters value can not reach real time when calculation,so study on the prediction error of EOP is helpful to improve the calculation accuracy of astronomy.Celestial fix and astronomical orientation principle was introduced in the paper,and the application of EOP parameters was studied,the accuracy of forecasted EOP parameters on short-term and long-term were analyzed respectively,studied the effects of EOP parameters error on astronomical positioning and orientation.The results show that,365_day daily forecasting value can be used in the calculation of latitude and azimuth for an astronomical measurement,but the calculation of longitude should update the prediction value each quarter.The astronomical navigation and astronomical measurement can use these conclusions for reference.