1. A method, comprising: displaying an augmented reality view on a display screen of an electronic device; creating a virtual excavation in a surface shown in the augmented reality view, the virtual excavation having a plurality of boundary surfaces that are defined by positions in three-dimensional (3-D) space of a 3-D model; calculating, by the electronic device, an intersection of positions of the plurality of boundary surfaces of the virtual excavation in the 3-D space of the 3-D model and 3-D ground penetrating radar (GPR) data that has been indexed in the 3-D space of the 3-D model; extracting, by the electronic device, data items of the 3-D GPR data that intersect the plurality of boundary surfaces of the virtual excavation to create a plurality of data sets, each data set corresponding to a respective one of the boundary surfaces of the virtual excavation; and for each data set, projecting a two-dimensional (2-D) image based on the extracted 3-D GPR data items of the data set onto the corresponding boundary surface of the virtual excavation in the augmented reality view, the 2-D image including colors or shading to show subsurface features determined from the extracted 3-D GPR data items.