Acta Geodaetica et Cartographica Sinica ›› 2018, Vol. 47 ›› Issue (S0): 71-77.doi: 10.11947/j.AGCS.2018.20180296

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Two Improved Algorithms for LS+AR Prediction Model of the Polar Motion

JIA Song1, XU Tianhe2,3, YANG Honglei2   

  1. 1. College of Surveying and Geo-information, Tongji University, Shanghai 200092, China;
    2. Institute of Space Science, Shandong University, Weihai 246209, China;
    3. State Key Laboratory of Geo-information Engineering, Xi'an 710054, China
  • Received:2018-06-24 Revised:2018-09-21 Online:2018-12-31 Published:2019-05-18
  • Supported by:
    The National Key Research and Development Program of China (No. 2016YFB0501701);The National Natural Science Foundation of China (Nos. 41874032;41574013)

Abstract: The polar motion(PM) is the important parameter to represent the earth movement, and the high-precision prediction of PM plays a key role in practical applications of astronomical research, the geodetic survey, navigation, aviation, ocean sounding and interplanetary navigation. Two modified algorithms are proposed to improve the PM prediction accuracy based on combination of least square and autoregressive model (LS+AR). One is to combine Kalman filtering (KF) to improve AR model accuracy, namely LS+AR+KF algorithm. The other is to use least mean square adaptive filtering (LMSAF) to improve the accuracies of LS fitting terms and predicting extrapolations, namely LS+AR+AF algorithm. The results show that LS+AR+KF and LS+AR+AF algorithms can significantly enhance the prediction accuracy of PM especially for long-term perdition, and LS+AR+AF is obviously superior to LS+AR and LS+AR+KF for PM prediction. The accuracy improvement of PM X component, PM Y component and PM can reach about 26%, 23% and 24% respectively, when using LS+AR+AF algorithm.

Key words: polar motion, prediction, Kalman filtering, least mean square, adaptive filtering

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