DTM 20 — ESRI GRID format

The digital model of the terrain is represented by a DTM with a grid structure with a sampling pitch of 20 meters, which can be used both to analyse the orographic trend of the Lombard territory, and to carry out studies of various types, being integrated with the other vector databases of the regional territorial information system. The coverage includes the hilly and mountainous areas of the Lombardy Region.GRID is a raster file developed by Esri, which has two formats: A proprietary binary format, also known as ARC/INFO GRID, ARC GRID and many other variants and a non-proprietary ASCII format, also known as GRID ASCII ARC/INFO.The binary format is widely used in Esri programs, such as ArcGIS, while the ASCII format is used as an exchange, or export format, thanks to the simple and portable structure. The GRID represents the geographical space as a square grid dot matrix of the same size consisting of rows and columns. Each point in the grid stores a numerical value that represents a geographical attribute (e.g. elevation or slope of the surface). Each cell in the grid is georeferenced.