An embodiment provides a method of modifying a CAD model. Such an embodiment associates metadata with a CAD model. In turn, the metadata is defined which includes providing the metadata in the form of a signal with one or more frequency characteristics that correspond to one or more respective characteristics of the CAD model. These frequencies can be used as part of mapping and/or processing algorithms in labeling or identifying unknown information about an environment. In an embodiment, the metadata may include graphical descriptions of the frequency such as vector or other image based files.