Analysing GNSS network data for deformation monitoring in multi-scale, multi-temporal civil engineering applications

变形监测是制定土木工程基础设施恢复力和可持续性战略以及应对地质灾害措施的关键要素。全球导航卫星系统站网络提供了一种监测工程结构运动的手段，可以在几秒到几年的时间尺度上检测局部（如单点）和更大规模（如国家）的结构运动。GNSS网络数据分析中的大多数策略是基于(i)恒定GNSS站速度，（ii） GNSS数据周期信号建模和（iii）最小二乘法来调整测量误差。这种策略是确定性方法，其中应用特定条件/约束（例如恒定速度）来模拟GNSS站的行为。此外，每个GNSS站都是单独分析的，而不检查附近和更远的其他GNSS站的行为，因为它们可能发生类似的行为。本研究项目将使用有待开发的技术，在分析全球导航卫星系统网络数据时采用不太确定的方法（例如人工智能），并采用将全球导航卫星系统数据视为网络一部分的空间分析方法。据推测，这些方法可以提取有关GNSS数据行为的更多信息，这些信息要么与GNSS特定台站有关，要么与GNSS网络的某个区域有关。该项目的目的是开发一种方法，在该方法中，GNSS网络数据将在时间和空间领域进行分析，并确定作为单个GNSS站和作为网络一部分的站的GNSS数据的行为。该方法将应用于各种工程项目的变形监测方案；(i)多尺度项目，从小型土木工程结构（例如桥梁）到大型工程，包括地质灾害领域（例如地面运动）；（ii）多时间变形，从短期（例如桥梁振动）到长期变形（例如地面沉降）。

Deformation monitoring is a key element to develop strategies of resilience and sustainability in civil engineering infrastructure and measures against geohazards. A network of GNSS stations provides a means to monitor the motions of engineering structures and enables both localised (e.g. single points) and larger scale (e.g. national) structural movements to be detected, over time scales of seconds to years. Most of the strategies in GNSS network data analysis are based on (i) constant GNSS station velocities, (ii) modelling of GNSS data periodic signals and (iii) least squares methods to adjust measurement errors. Such strategies are deterministic approaches, where specific conditions/constraints are applied (e.g. constant velocity) to model the behaviour of the GNSS stations. Furthermore, each GNSS station is analysed individually, without examining the behaviour of other GNSS stations, both nearby and further afield, at which similar behaviour may be occurring. This research project will use to-be-developed techniques, following less deterministic approaches (e.g. artificial intelligence) in the analysis of the GNSS network data and adopting spatial analysis methods which treat the GNSS data as part of a network. It is hypothesised that these approaches could enable the extraction of more information regarding the behaviour of the GNSS data, either related locally to a GNSS-specific station or related to a region of the GNSS network. The aim of this project is to develop a methodology where the GNSS network data will be analysed in both the time and space domains and identify the behaviour of the GNSS data of the stations, as individual GNSS stations and as part of the network. This methodology will be applied to deformation monitoring scenarios from a broad range of engineering projects; (i) multi-scale projects, from small scale civil engineering structures (e.g. bridges) to larger scale including the field of geohazards (e.g. ground motion) and (ii) multi-temporal deformations, from short-term (e.g. bridge vibration) to long-term deformation (e.g. land subsidence).