基于有色噪声滤波的铁路工程基础设施GPS/BDS变形监测应用与技术挑战OA

At present,railway projects mostly use single Beidou positioning technology to monitor the deformation of a single type of infrastructure,and lack analysis of monitoring accuracy for multiple infrastructures under combined modes of Beidou and other GNSS(Global Navigation Satellite System)systems,while the adverse effects of colored noise on the monitoring results are ignored.In order to ensure the applicability of Beidou positioning technology to the deformation monitoring of different railway infrastructures and improve the monitoring accuracy,this paper introduced the colored noise filtering method and used GPS/BDS positioning technology to conduct short-term and long-term deformation monitoring of two types of infrastructures:large-span cable-stayed bridges and high slopes at tunnel entrances.For large-span cable-stayed bridges,the instantaneous deformation,natural frequency and short-term periodic deformation of key positions of the bridge under load were monitored.For high slopes at tunnel entrances,the long-term displacement trend of the slope was monitored.The experimental results showed that the high-frequency GPS/BDS deformation monitoring accurately captured the instantaneous deformation characteristics of railway bridges under train loads and identified the natural frequencies of bridges.By applying colored noise filtering,the influence of flicker noise in the deformation monitoring time series was significantly weakened,the amplitude of the flicker noise was reduced by about 75%,and the uncertainties of the short-term periodic deformation parameters of the railway bridge and the estimation of the long-term linear deformation parameters of the slope were reduced by about 88%,which significantly improved the reliability of the deformation analysis results.The challenges of GPS/BDS deformation monitoring considering colored noise filtering in mountainous environments with extremely complex geological conditions were also discussed.A deformation monitoring time series preprocessing strategy combining the application of zenith tropospheric delay correction,environmental load model optimization,and step correction model of topographic elevation difference was proposed,aiming to further improve the estimation accuracy of deformation parameters.