Spurious draconitic errors with periods of (351.4/N) days are detected in GPS position time series. This study assesses the performance of ambiguity resolution in sub-daily position estimates on reducing the draconitic errors. Precise point positioning solutions covering 132 global stations from 2002 to 2017 are generated with and without ambiguity resolution using 24-, 8- and 4-h processing sessions. Different satellite products from the European Space Agency (ESA) and the Massachusetts Institute of Technology (MIT) are employed. Although the ambiguity fixing rate decreases with the processing session shortening, a higher percentage of the draconitic errors are reduced by ambiguity resolution for nearly all the solutions and components (but the East component of ESA 4-h solution). At its best, fixing ambiguities reduces the draconitic errors by more than 60% in the East component and by about 20% in the North and Up components for 4-h solutions. Moreover, the draconitic errors and their reduction by ambiguity resolution show a latitudinal dependence. The draconitic errors are also reduced by sub-daily solutions with the largest reduction of 25.4%, 12.6% and 25.3% in the North, East and Up components, respectively, for ESA 4-h solution with ambiguity resolution, but less reduction for MIT solutions. It indicates that part of the draconitic errors result from the alias of certain unmodeled diurnal and semidiurnal signals beating against standard 24-h processing, and these signals mainly come from orbit-related errors, rather than station-specific errors.

在GPS位置时间序列中检测到周期为（351.4 / N）天的虚假严重误差。这项研究评估了次日位置估计中减少歧义误差的歧义解决方案的性能。使用24、8和4小时处理会话，可以生成含或不含歧义分辨率的精确点定位解决方案，涵盖2002年至2017年的132个全球站点。使用了来自欧洲航天局（ESA）和麻省理工学院（MIT）的不同卫星产品。尽管歧义修复率随着处理会话时间的缩短而降低，但几乎所有解决方案和组件（但ESA 4-h解决方案的East组件）的歧义解决方案都减少了较高百分比的剧烈误差。最好的时候 对于4小时解决方案，固定歧义可将东部部分的剧烈误差减少60％以上，将北部和北部部分的戏剧性误差减少20％以上。此外，严重误差及其通过歧义解决方法的减少显示出纬度依赖性。次日解决方案还可以减少严重误差，对于含歧义度的ESA 4-h解决方案，在北部，东部和北部地区，最大的减少幅度分别为25.4％，12.6％和25.3％，但对于MIT的减少幅度较小解决方案。它表明，部分严重的误差是由于某些未建模的昼夜和半昼间信号击败了标准的24小时制而造成的，这些信号主要来自与轨道有关的误差，而不是特定于站的误差。