Railway track transitions are prone to uneven settlements and track geometry degradation. Traditional monitoring methods are limited in coverage, which highlights the need for novel solutions. This study proposes a method that systematically integrates the high spatial resolution of Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) with the broader coverage of Small Baseline Subset (SBAS). A correction method for abnormal InSAR time series is developed, considering both consecutive phase unwrapping errors as well as outlier displacements. Model parameters are optimized through Monte Carlo analysis embedded with grid search. The proposed PS-SBAS InSAR processing method is applied to generate the track longitudinal profile of a railway transition section and is compared with track inspection data. The results show: (1) the hybrid PS-SBAS approach provides higher resolution and robustness for tracking long-term differential settlement along railway tracks. (2) There is a strong correlation between track longitudinal level and the InSAR-derived profile in the bridge approaches with high differential settlement rates. (3) InSAR can serve as a complementary method to traditional inspections, capturing the progression of differential settlement and enhancing the understanding of long-term settlement patterns and their impact on track performance.

中文翻译：

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基于卫星遥感技术的铁路过渡区差异沉降监测

铁路轨道过渡容易出现不均匀沉降和轨道几何退化。传统的监测方法覆盖范围有限，这凸显了对新型解决方案的需求。该文提出了一种系统地将持续散射干涉合成孔径雷达 （PS-InSAR） 的高空间分辨率与小基线子集 （SBAS） 覆盖范围相结合的方法。该文提出了一种针对异常 InSAR 时间序列的校正方法，该方法同时考虑了连续相位解缠误差和异常值位移。通过嵌入网格搜索的 Monte Carlo 分析来优化模型参数。该文采用所提出的 PS-SBAS InSAR 处理方法生成铁路过渡段的轨道纵向剖面，并与轨道巡检数据进行比较。结果表明：（1）混合 PS-SBAS 方法为跟踪铁路轨道上的长期差分沉降提供了更高的分辨率和鲁棒性。（2） 在具有高差分沉降率的桥梁进场中，航迹纵向水平与 InSAR 衍生的剖面之间存在很强的相关性。（3） InSAR 可以作为传统检查的补充方法，捕捉差异沉降的进展，并增强对长期沉降模式及其对轨道性能影响的理解。