Afana, A, Hunter, G, Rosser, N, Williams, J & Hardy, R 2015, 'Increasing reliability in terrestrial laser data for slope failure monitoring', in PM Dight (ed.), FMGM 2015: Proceedings of the Ninth Symposium on Field Measurements in Geomechanics, Australian Centre for Geomechanics, Perth, pp. 809-818, https://doi.org/10.36487/ACG_rep/1508_60_Afana
(https://papers.acg.uwa.edu.au/p/1508_60_Afana/)
Abstract: Terrestrial laser scanning (TLS) has provided new capabilities for real-time slope failure monitoring. For the mining industry, the advantages of TLS are not limited to deformation monitoring but also include a wide range of geotechnical and surveying applications such as characterising rockfall, 3D rock mass structure, and delineating features. Precision, repeatability and accuracy are crucial for deformation measurement. However, TLS data is affected by local climatic variations, such as fluctuations in temperature, rainfall, humidity, irradiance, and ambient light conditions. This is widely observed in open pit mines where high ranges (>2 km), often high temperature gradients and extremes, and steep topography result in highly variable measurement quality. As such, diurnal variations in ranging precision from TLS systems in such locations can reach up to 30-40 millimetres in some cases. 
A direct-Fourier transformation method applied to sequentially captured time-series of TLS data is proposed to overcome such variability. By modelling diurnal fluctuations in range from independently monitored environmental variables, it is possible to estimate the frequency and phase characteristics of these effects. Discrimination between deformation and environmentally modulated cyclicity is achieved by modelling out trends in the TLS data. Results contribute to improving the precision of slope failure warning systems as a tool to enhance safety procedures for sustainable mining activities.