  Aiming at the problem that GNSS-RTK technology cannot effectively monitor
landslides due to gross errors and high-frequency noise during landslide
monitoring, a GNSS-RTK landslide monitoring system based on the improved Raida
criterion(3{\sigma}) was designed. The system uses Raspberry Pi as the control
core, GNSS-RTK technology to complete deformation data collection, and combines
NB-IoT to achieve data transmission and cloud storage. To further improve the
monitoring accuracy, real-time gross error detection and high-frequency noise
removal method based on the improved Raida criterion(3{\sigma}) and Butterworth
low-pass filtering is proposed, combined with edge computing devices to
complete real-time data processing, and reduce the pressure of cloud computing.
The experimental results show that the system's data transmission is reliable
and efficient. After gross error elimination and noise processing, real-time
deformation monitoring of 10 mm in the horizontal and vertical directions is
achieved; simultaneously, the monitoring error of the GNSS combined system is
smaller than that of the Single-GPS system.
