02. Improving positional accuracy in deformation monitoring using GNSS RTK

Abstract

The automatic monitoring system has been widely applied for structure deformation monitoring. A monitoring system consists of many automatic monitoring sensor stations installed at specific locations of the project site, with the aim of monitoring different quantities such as displacement, settlement, inclination,... All stations are generally connected to a control system through software, transmission of real-time monitoring data of the monitored objects. Monitoring data can be analyzed and evaluated over time for reporting its health status. Due to the influence of the environment and different measurement conditions, the measurement data is often affected by noise, causing measurement errors. Therefore, noise filtering is necessary in the processing of monitoring data to ensure the accuracy of measurement results. With real-time continuous monitoring data with a frequency from a few seconds to a few minutes, we propose an extended Kalman filter with parameters suitable for current monitoring conditions in Vietnam. The main objective of the paper is to build a mathematical model for extended Kalman filtering in automatic continuous construction displacement monitoring. Research results show that when applying filters to process monitoring data, the accuracy and reliability of monitoring results increase significantly compared to untreated data. Observation accuracy reached 3.9 - 6.0 mm with a data collection interval of 1 minute.