A precise Global Navigation Satellite System (GNSS) satellite orbit is an essential prerequisite for precise point positioning (PPP). Due to the daily orbit discontinuities (DODs) between adjacent daily orbit products provided by the International GNSS Service, the interpolation accuracy at the epochs near the day boundaries cannot be as high as expected and can significantly degrade the positioning accuracy. This is especially for the emerging Beidou and Galileo satellites with larger DODs. In this study, a new interpolation strategy was proposed to mitigate the DOD effect by estimating the zero- to second-order biases between the orbits of two adjacent days. The results show that the proposed interpolation strategy outperforms the traditional interpolation strategies. The 3D orbit interpolation error for the last 10 min on each day is reduced from almost a few centimeters or even meters to millimeters, an improvement of approximately 86–99% for all satellites. PPP validation also provides concrete evidence of this improvement, as the DOD-induced satellite phase residuals are reduced significantly. Thus, the new interpolation strategy mitigates the DOD effect and helps multi-GNSS users obtain the highest interpolation accuracy at the day boundaries, which can be comparable to that at the non-day boundaries.

精确的全球导航卫星系统（GNSS）卫星轨道是精确点定位（PPP）的必要先决条件。由于国际GNSS服务提供的相邻日轨道产品之间的日轨道不连续性（DOD），在日边界附近的历元的插值精度无法达到预期的水平，并且会大大降低定位精度。特别是对于具有较大DOD的新兴北斗和伽利略卫星。在这项研究中，提出了一种新的插值策略，通过估算相邻两天轨道之间的零阶至二阶偏差来减轻DOD效应。结果表明，提出的插值策略优于传统的插值策略。每天最后10分钟的3D轨道插值误差从几厘米甚至几米减小到毫米，所有卫星的误差都提高了约86–99％。PPP验证也提供了这种改进的具体证据，因为DOD引起的卫星相位残差大大减少了。因此，新的插值策略减轻了DOD效应，并帮助多GNSS用户在日边界上获得了最高的插值精度，该精度可与非日边界上的精度相媲美。