The pseudorange and phase residuals for the IF-PPP at HKLM station on DOY 122. The residuals are calculated as the differences between the observed and modeled values. Pseudorange residuals are shown on the left, while carrier phase residuals are shown on the right. Each satellite used in the solution is marked with a different color along the time axis. These residuals reflect the quality of the observation data and the performance of the IF-PPP model under ionospheric scintillation conditions.