Enhancing Real-Time Kinematic Positioning Precision in Large Height Variations: A Novel Periodic Term-Based Correction Method

The positioning accuracy of real-time kinematic (RTK) technology is closely related to the height differences between stations. When the height difference is large, the correlation between the tropospheric delay errors at different stations weakens, and, as a result, the positioning accuracy often fails to meet engineering application requirements. In this paper, a method for correcting the positioning results of RTK with large height differences based on the periodic term is proposed. This paper takes the monitoring baseline with a height difference of about 280 m as the research object, adopts polynomial fitting and Fourier transform methods to conduct spectral analysis of a time series of historical results, extracts the significant trend and periodic terms in the local historical results, and then makes a real-time correction to the real-time positioning results when the real-time positioning solution results are output. The experimental results indicate that, after applying the correction to the positioning results, the standard deviation decreased from 1.98 to 0.95 cm, representing an improvement of 52.17%. The results demonstrate that the proposed method can effectively reduce the cyclic fluctuations in the vertical direction for large height difference RTK and significantly improve the accuracy and reliability of the monitoring results.