Physical Models

A 3D presentation needs two kinds of data; a Digital Elevation Model (DEM) and an image to be displayed on the model.

The required resolution of both the DEM and of the image will depend upon the scale of model that is desired. Many commercial DEMs exist that will meet the requirements of most regional models. Large scale models such a one that may show an area equivalent in size to a few city blocks, may require a more detailed DEM that could be generated from local topographic contours or other survey data.

The imagery that is print on the model will depend upon the scale of model and its’ purpose. Common sources of imagery include satellite images such as Landsat, IRS and RADARSAT data for regional scale models. Models requiring a higher level of visual detail can be created using orothorectified aerial photographs. GIS data can always be combined with either satellite or aerial photos to enhance the presentation or used by itself for thematic purposes.