TERRA - Intro to Remote Rock Mass Characterization

Aperture is the thickness of a fracture and it dictates how open or close the fracture is. It's an important parameter as it determines the amount and transport of fluid flow through a fracture.

Block size is a key parameter in rock mass characterization and is one of the fracture properties. It determines the degree of fracturing in a rock mass and is related to spacing and persistence. It gives a measure of the rock mass strength degradation and influences the amount and type of ground support needed.

CloudCompare is a 3-D point cloud editing software which uses 3-D point clouds as an import and performs various measurements and analysis on them. It can also handle triangular meshes and calibrated images. 

Compass plugin is a structural geology toolbox for the interpretation and analysis of virtual outcrop models. It's a plugin used in CloudCompare to measure the orientations of fully exposed planar structures like joints or bedding planes. https://www.cloudcompare.org/doc/wiki/index.php/Compass_(plugin)

Depth of field (FoV) is the distance between the nearest and the furthest objects that are in sharp focus of the camera. It determines the sharpness of the image. The aperture determines depth of field. A small aperture reflects high sharpness in the image.

Discontinuities are natural interruptions in the intact rock that impact the overall rock mass behavior under load and fluid flow. Discontinuities consist of fractures, joints, faults, shear zones, and bedding planes. 

Discontinuity Set Extractor (DSE) is a clustering based software that is used to extract discontinuity sets from a point cloud. It was developed by Adrián Riquelme as part of his PhD studies. Find more about DSE in https://rua.ua.es/dspace/bitstream/10045/50025/2/Discontinuity-Set-Extractor-software.pdf

A discrete fracture network (DFN) is a statistical distribution of fractures in the rock mass. Fractures are spatially variable, and their hydromechanical parameters are more accurately described by statistical distributions. DFNs provide a more probabilistic approach to record the degree of fracturing in a rock mass.

A fracture is a general type of discontinuity that is crucial from geotechnical point of view. It's a natural breakage in a rock mass and along its plane, there may or may not have been any displacement. Fractures differ from joints from a structural geology point of view. Joints have little or no displacement. 

Fracture intensity refers to the number of fractures in a given rock mass. It is often denoted as P32 which is the area of fractures per unit volume.