A digital terrain model (DTM) is a topographic model of the "bare earth" that enables users to infer terrain characteristics that may be hidden in the digital surface model (DSM). A DTM has had vegetation, buildings, and other cultural features digitally removed, leaving just the underlying terrain. This is achieved using a proprietary software application, manual editing, and a quality control process that derives terrain elevations based on measurements of bare ground contained in the original radar data.
Our Topographical surveys are surveyed in 3D. Therefore in addition to providing contoured plans, we are able to provide 3D digital terrain models (DTMs) on disk. This is a computer generated "wire-frame" model of the topography of the site. These can be rendered if required. We create DTMs for most topographical surveys that we carry out; as this is used for the creation of the site contours. We can also produce site cross-sections by utilising this information, if required. We often provide 3D "triangle" file DTMs to clients for them to use for site volume calculations, optimum design levels etc..