“…In recent years, the filter random model has been optimized by GMM, which has gradually been recognized as a superior approach, attracting attention in target tracking, speech recognition, signal analysis, navigation integrity monitoring, and other aspects ( Sun et al, 2020 ; Zickert and Yarman, 2021 ; Zhu et al, 2022 ; Yu et al, 2023 ). The literature sequentially delves into the nonlinear optimization problem associated with the Gaussian sum filter (GSF) algorithm grounded in GMM, such as the Gaussian sum extended Kalman filter (GSEKF) algorithm, Gaussian sum unscented Kalman filter (GSUKF) algorithm, Gaussian sum quadrature Kalman Filter (GSQKF) algorithm, and Gaussian sum cubature Kalman filter (GSCKF) algorithm, and these studies have to some extent optimized the integrated navigation information fusion algorithm ( Wang and Cheng, 2015 ; Qian et al, 2021 ; Wang et al, 2021 ; Bai et al, 2022 ). While numerous algorithms have been put forward to optimize the random model of nonlinear filter algorithms under non-Gaussian noise conditions based on GMM, there are limited reports on research on quaternion-based algorithm in GNSS/SINS-IADPS data processing for UAVs.…”