For more than 20 years, precise point positioning (PPP) has been a well-established technique for carrier phase-based navigation. Traditionally, it relies on precise orbit and clock products to achieve accuracies in the order of centimeters. With the modernization of legacy GNSS constellations and the introduction of new systems such as Galileo, a continued reduction in the signal-in-space range error (SISRE) can be observed. Supported by this fact, we analyze the feasibility and performance of PPP with broadcast ephemerides and observations of Galileo and GPS. Two different functional models for compensation of SISREs are assessed: process noise in the ambiguity states and the explicit estimation of a SISRE state for each channel. Tests performed with permanent reference stations show that the position can be estimated in kinematic conditions with an average three-dimensional (3D) root mean square (RMS) error of 29 cm for Galileo and 63 cm for GPS. Dual-constellation solutions can further improve the accuracy to 25 cm. Compared to standard algorithms without SISRE compensation, the proposed PPP approaches offer a 40% performance improvement for Galileo and 70% for GPS when working with broadcast ephemerides. An additional test with observations taken on a boat ride yielded 3D RMS accuracy of 39 cm for Galileo, 41 cm for GPS, and 27 cm for dual-constellation processing compared to a real-time kinematic reference solution. Compared to the use of process noise in the phase ambiguity estimation, the explicit estimation of SISRE states yields a slightly improved robustness and accuracy at the expense of increased algorithmic complexity. Overall, the test results demonstrate that the application of broadcast ephemerides in a PPP model is feasible with modern GNSS constellations and able to reach accuracies in the order of few decimeters when using proper SISRE compensation techniques.

20多年来，精确点定位（PPP）已成为基于载波相位导航的成熟技术。传统上，它依靠精确的轨道和时钟产品来实现厘米级的精度。随着传统GNSS星座的现代化和引入新系统（如Galileo），可以观察到空间信号范围误差（SISRE）的持续降低。在这一事实的支持下，我们通过广播星历表以及伽利略和GPS观测资料分析了PPP的可行性和性能。评估了两种不同的SISRE补偿功能模型：歧义状态下的过程噪声和每个通道的SISRE状态的显式估计。使用永久参考站进行的测试表明，可以在运动条件下估计位置，伽利略（Galileo）的平均三维（3D）均方根（RMS）误差为29厘米，GPS的平均三维均方根（RMS）误差为63厘米。双星座解决方案可以将精度进一步提高到25厘米。与没有SISRE补偿的标准算法相比，与广播星历表一起使用时，建议的PPP方法将Galileo的性能提高40％，将GPS的性能提高70％。与实时运动参考解决方案相比，在乘船观察时进行的另一项测试得出的3D RMS精度，伽利略（Galileo）为39厘米，GPS为41厘米，双星座处理为27厘米。与在相位模糊度估算中使用过程噪声相比，SISRE状态的显式估计会略微提高鲁棒性和准确性，但会增加算法的复杂性。总体而言，测试结果表明，在现代GNSS星座中，将广播星历表应用于PPP模型是可行的，并且使用适当的SISRE补偿技术时，能够达到几分米的精度。