## 4 Application Scenarios of the Multipath Error Mitigation Algorithm  
### GNSS Deformation Monitoring  
Since its development in the 1970s, the GNSS has become an indispensable part of space technology in the new century. With its advantages of high positioning accuracy, fast positioning speed, and precise timing [88], it has been applied in many disciplines, such as transportation, surveying and mapping, communications, deformation monitoring, precision agriculture, machinery control, and the monitoring and forecasting of geological hazards [89]. Since the 1990s, GNSS technology has been applied to deformation monitoring. Figure 4: Flowchart of the MHM algorithm based on the observation domain. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Type** & **Method** & **Experimental Scene** & **System** & **Year** & **Scholar** \\ \hline \multirow{8}{*}{Coordinate domain} & CVVF & Baseline positioning & GPS & 2005 & [PERSON] [42] \\  & EMD & Baseline positioning & GPS & 2006 & [PERSON] [43] \\  & Wavelet signal-layer automatic identification & Baseline positioning & GPS & 2008 & [PERSON] [50] \\  & EMD & Baseline positioning & GPS & 2012 & [PERSON] [44] \\  & PCA-EMD-ICA-R & Baseline positioning & GPS & 2014 & [PERSON] [51] \\  & SSA & Baseline positioning & GPS & 2015 & [PERSON] [49] \\  & CEEMD & Baseline positioning & GPS & 2018 & [PERSON] [45] \\  & GED & Baseline positioning & BDS & 2018 & [PERSON] [47] \\  & EMD-RLS & Baseline positioning & BDS & 2019 & [PERSON] [48] \\  & EWT & Baseline positioning & GPS & 2020 & [PERSON] [52] \\  & Wavelet analysis & Baseline positioning & GPS & 2021 & [PERSON] [53] \\  & Least-squares harmonic estimation & Baseline positioning & GNSS & 2022 & [PERSON] [54] \\  & AF-ICA & Baseline positioning & GNSS & 2022 & [PERSON] [55] \\  & CEEMDAN-WT & Baseline positioning & GPS, BDS & 2022 & [PERSON] [46] \\ \hline \multirow{8}{*}{Observation domain} & Wavelet analysis & Baseline positioning & GPS & 2005 & Satisfomed [62] \\  & Wavelet detrending technique & Baseline positioning & GPS & 2009 & [PERSON] [63] \\  & SF based on single differences & Baseline positioning & GNSS & 2010 & [PERSON] [57] \\  & Three-level wavelet packet-based & & Baseline positioning & GPS & 2017 & [PERSON] [66] \\  & denoising method & Baseline positioning & GPS & 2018 & [PERSON] [65] \\  & KF-RTS & Baseline positioning & BDS & 2018 & [PERSON] [65] \\  & MHM-V & Baseline positioning & GPS & 2021 & [PERSON] [86] \\  & MHM based on EEMD & Baseline positioning & GNSS & 2022 & [PERSON] [87] \\  & SF based on EC wavelet packet transform & Baseline positioning & GNSS & 2022 & [PERSON] [67] \\  & SF-based sym6 wavelet decomposition & Baseline positioning & BDS & 2022 & [PERSON] [73] \\  & Window-matching method based on SF & Baseline positioning & GPS, BDS & 2022 & [PERSON] [61] \\  & RWM & Baseline positioning & Galileo & 2023 & [PERSON] [57] \\  & LSC & Baseline positioning, FPP & GPS, Galileo & 2023 & [PERSON] [76] \\ \hline \hline \end{tabular}
\end{table} 
Table 5: A summary of the popular multipath error mitigation methods. Compared with traditional deformation monitoring, GNSS monitoring technology has unique advantages in large-scale structural health monitoring: high sampling rate, no need to supervise it, high degree of automation, four-dimensional monitoring, and all-weather monitoring [90]. GNSS monitoring technology can be applied to various monitoring scenarios to meet different monitoring requirements, such as monitoring types, monitoring accuracy, monitoring instruments, and monitoring range [91]. The GNSS deformation monitoring system is an important and effective way to obtain structure safety and health monitoring data. In the monitoring of specific projects, GNSS monitoring technology can obtain the high-precision deformation of structures, obtain vibration signals, and achieve the simultaneous monitoring of real-time and long-term deformation of structures [92].