Abstract: [Purposes] To investigate the impact of ionospheric disturbances during geomagnetic storms on GNSS static positioning accuracy，this paper analyzes the ionospheric characteristics and GNSS positioning performance during the geomagnetic storm in November 2023. [Methods] Based on observation data from Kunming CORS reference stations，the ionospheric delay is computed using the uncombined precise point positioning (PPP) algorithm.The vertical total electron content (VTEC) interpolated from global ionospheric maps (GIM)is adopted to determine the upper and lower bounds of the disturbance background via the sliding interquartile range method，so as to identify and extract ionospheric disturbances during the storm.The effects of ionospheric disturbances on GNSS static positioning accuracy are evaluated using indicators including synchronous loop and asynchronous loop closure errors. [Findings] The experimental results show that signal scintillation caused by ionospheric irregularities during the geomagnetic storm is the main factor degrading GNSS static positioning accuracy.Under the 4 h observation duration，the relative accuracies of the three positioning schemes fail to meet the 1×10^-6 requirement for Class C networks. [Conclusions] The results clarify the ionospheric response characteristics and their significant influence on GNSS static positioning during the November 2023 geomagnetic storm，which provides guidance for GNSS static positioning surveys．

Key words: geomagnetic storm, ionospheric disturbance, sliding interquartile range method, rate of TEC index, GNSS static positioning