Working with HRT point clouds presents many challenges. HRT point cloud processing is not the focus of this course. However, ToPCAT developed by Brasington et al. (2012) provides some practical methods for statistical analysis of point clouds and decimation of datasets to more manageable sizes for traditional raster-based change detection:
Brasington J, Vericat D and Rychkov I. 2012. Modeling river bed morphology, roughness, and surface sedimentology using high resolution terrestrial laser scanning. Water Resources Research. 48(11). DOI: 10.1029/2012wr012223.
For follow up reading and more sophisticated alternatives to ToPCAT for working with point clouds, see Dimitri Lague's work on doing cloud to cloud analyses (e.g. Lague et al. 2013) and Dan Buscombe's work using spectral analyses of point clouds (e.g. Buscombe 2016):
Lague D, Brodu N and Leroux J. 2013. Accurate 3D comparison of complex topography with terrestrial laser scanner : application to the Rangitikei canyon (NZ). ISPRS journal of Photogrammmetry and Remote Sensing. 82: 10-26. DOI: 10.1016/j.isprsjprs.2013.04.009.