A NEW SURVEYING TECHNOLOGY FOR RAILWAY SUBGRADE SETTLEMENT DEFORMATION MONITORING: A CASE STUDY

摘要

Satellite differential interferometric synthetic aperture radar technology (D-InSAR) is an innovative measurement method developing rapidly during recent years in photogrammetry and remote sensing field. To test and demonstrate its applicability to deformation monitoring for railway subgrade settlement, this paper introduces the technical performances of DInSAR, and analyzes its feasibility for measurement of high-speed railway subgrade settlement. As a case study experiment, persistent scatterers (PS) interferometry using satellite D-InSAR technology was applied to detect subgrade deformation over permafrost regions of Qinghai-Tibet Plateau in the Beiluhe test site along the Qinghai-Tibet railway with gathered ENVISAT-ASAR images. The experimental results show that PS interferometry can effectively acquire long-time deformation sequence through analyzing the ground scatterers with relative stable phase and are in accordance with the results obtained by conventional in-situ ground leveling. The deformation characteristics of the sliced rock embankment and railway bridge along the Qinghai-Tibet railway are analyzed and compared.