While optical remote sensing has demonstrated its capabilities for landslide detection and monitoring, spatial and temporal demands for landslide early warning systems (LEWSs) had not been met until recently. We introduce a novel conceptual approach to structure and quantitatively assess lead time for LEWSs. We analysed “time to warning” as a sequence: (i) time to collect, (ii) time to process and (iii) time to evaluate relevant optical data. The difference between the time to warning and “forecasting window” (i.e. time from hazard becoming predictable until event) is the lead time for reactive measures. We tested digital image correlation (DIC) of best-suited spatiotemporal techniques, i.e. 3 m resolution PlanetScope daily imagery and 0.16 m resolution unmanned aerial system (UAS)-derived orthophotos to reveal fast ground displacement and acceleration of a deep-seated, complex alpine mass movement leading to massive debris flow events. The time to warning for the UAS/PlanetScope totals 31/21 h and is comprised of time to (i) collect – 12/14 h, (ii) process – 17/5 h and (iii) evaluate – 2/2 h, which is well below the forecasting window for recent benchmarks and facilitates a lead time for reactive measures. We show optical remote sensing data can support LEWSs with a sufficiently fast processing time, demonstrating the feasibility of optical sensors for LEWSs.

中文翻译：

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多光谱遥感滑坡预警系统的及时预测潜力：在奥地利萨特尔卡测试的概念方法

虽然光学遥感已经证明了其滑坡检测和监测的能力，但直到最近才满足滑坡预警系统 (LEWS) 的空间和时间需求。我们引入了一种新的概念方法来构建和定量评估 LEWS 的提前期。我们将“警告时间”分析为一个序列：（i）收集时间，（ii）处理时间和（iii）评估相关光学数据的时间。预警时间和“预测窗口”（即从危险变为可预测到事件发生的时间）之间的差异是反应性措施的提前期。我们测试了最适合时空技术的数字图像相关性 (DIC)，即 3 m 分辨率的 PlanetScope 每日图像和 0. 分辨率为 16 m 的无人机系统 (UAS) 衍生的正射影像揭示了导致大规模泥石流事件的深层复杂高山物质运动的快速地面位移和加速度。UAS/PlanetScope 的警告时间总计 31/21 小时，包括以下时间：(i) 收集 – 12/14 小时，(ii) 处理 – 17/5 小时和 (iii) 评估 – 2/2 小时，这远低于近期基准的预测窗口，并有助于缩短反应性措施的提前期。我们展示了光学遥感数据可以以足够快的处理时间支持 LEWS，证明了光学传感器用于 LEWS 的可行性。(ii) 过程 – 17/5 小时和 (iii) 评估 – 2/2 小时，这远低于最近基准的预测窗口，并有利于反应性措施的提前期。我们展示了光学遥感数据可以以足够快的处理时间支持 LEWS，证明了光学传感器用于 LEWS 的可行性。(ii) 过程 – 17/5 小时和 (iii) 评估 – 2/2 小时，这远低于最近基准的预测窗口，并有利于反应性措施的提前期。我们展示了光学遥感数据可以以足够快的处理时间支持 LEWS，证明了光学传感器用于 LEWS 的可行性。