Optimising the quality of an SfM‐MVS slope monitoring system using fixed cameras

Abstract The quality of 3D scene reconstruction and monitoring through structure‐from‐motion multiview stereo (SfM‐ MVS ) depends on critical key factors, including camera calibration and image network geometry. The goal of this paper is to examine the monitoring ability of an SfM‐ MVS workflow based on four or more ground‐based digital single‐lens reflex ( DSLR ) cameras and to estimate differences when adopting both fixed and variable camera positions and orientations. This was achieved by conducting work on a scaled laboratory testfield and a sea cliff. Tests demonstrate that a monitoring system using just four fixed cameras can achieve valuable monitoring capabilities and tolerate imperfections in the camera calibration. Furthermore, such a configuration can achieve accuracies comparable to terrestrial laser scanning ( TLS ) and drone‐based photogrammetry. The study demonstrates that minimising registration errors between point clouds is critical. The “registration SIFT ” approach could resolve such problems.