Landslides are one of the major factors threatening human life and social development. Monitoring and early warning of landslides are important parts of disaster prevention and control. However, due to complex terrain conditions, landslide monitoring in mountainous watersheds and high mountain valleys usually faces issues of high difficulty, high danger, poor data integrity, and low data accuracy compared with plains or hilly areas. Based on the fusion of terrestrial laser scanning (TLS) and unmanned aerial vehicle (UAV) photogrammetry, this article proposes a landslide deformation monitoring method that can be applied to complex terrain conditions where there are access restrictions and blind areas. The method is based on TLS to increase the number and range of ground control points (GCPs) of UAVs within the visual range and then uses assumed control points (ACPs) to reconstruct the UAV model and calculate landslide displacement in invisible areas. In addition, this article proposes and verifies a formula based on an allometricl equation to estimate the error between the calculated and real displacements based on this method. Then, we applied this method to a real landslide case and successfully realized landslide monitoring under the conditions of access limitation and blind areas. The proposed method enables landslide monitoring to overcome terrain restrictions, and it makes it possible to perform large-scale and high-precision ground deformation measurements with limited working ranges, which can be an effective tool for landslide monitoring in emergency situations and long-term risk evaluation.

中文翻译：

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基于地面激光扫描和无人机摄影测量的复杂地形条件下滑坡变形监测的融合方法

滑坡是威胁人类生活和社会发展的主要因素之一。滑坡监测预警是灾害防治的重要组成部分。然而，由于地形条件复杂，山区流域和高山山谷滑坡监测与平原或丘陵地区相比，通常面临难度大、危险性大、数据完整性差、数据准确率低等问题。本文基于地面激光扫描（TLS）和无人机（UAV）摄影测量的融合，提出了一种适用于有通道限制和盲区的复杂地形条件的滑坡变形监测方法。该方法基于TLS在可视范围内增加无人机地面控制点（GCP）的数量和范围，然后使用假设控制点（ACP）重建无人机模型并计算不可见区域的滑坡位移。此外，本文提出并验证了一个基于异速生长方程的公式，用于估计基于该方法的计算位移与实际位移之间的误差。然后，我们将该方法应用到一个真实的滑坡案例中，并成功实现了在通道受限和盲区条件下的滑坡监测。所提出的方法使滑坡监测能够克服地形限制，并且可以在有限的工作范围内进行大规模和高精度的地面变形测量，