Surface formats

As with any geospatial information, surfaces need to be organized and stored on computers for access, management, visualization, and distribution. With ArcGIS, there are two approaches for managing your surface data: geodatabase or file-based. The method you choose is partially your choice but is also limited by the surface type.

Geodatabases are collections of spatial data native to ArcGIS that collate several features or raster datasets all in one place. ArcGIS offers three types of geodatabases: personal, file, and multiuser.

File-based formats can be ESRI specific (TIN, GRID), open-source and standardized exchange formats (TIFF, JPEG2000), or third-party formats (IMG, PIX). ArcGIS supports many file-based formats.

Surface types

There are three types of surface models available in ArcGIS: raster, TIN, and terrain datasets. Each surface type is stored according to its characteristics.

Raster surfaces

Surfaces that are raster in nature can be stored in a personal, file, or multiuser geodatabase. There are two methods for storing rasters in a geodatabase. Raster datasets are individual rasters that are a single matrix of rows and columns. A mosaic of imagery is considered a raster dataset. The other method for storage of rasters in a geodatabase (personal, file, or ArcSDE) is as a raster catalog, which is a collection of several raster datasets.

Learn more about storing rasters in a geodatabase

Raster surfaces can also be stored in file-based solutions. In this format, all the information is stored in a file or series of files that comprise the raster data. A tagged image file format (TIFF) is an example of a file-based surface storage solution. ESRI Grid is an ESRI-specific format that is not just a single file but a folder with a collection of files that are all interdependent. The bitdepth (the number of bits that each cell can store) varies from format to format, so be sure to choose an appropriate file format for your data. For a complete list of file-based raster formats that ArcGIS supports, see Technical specifications for raster dataset formats.

TIN surfaces

Triangulated irregular networks (TINs) are the vector equivalent of raster-based surfaces. A series of nodes are joined together by triangular faces that represent the surface for display. Theoretically, any z-value on the face of the triangle can be calculated to a defined degree of accuracy. TINs cannot be stored in any of the three types of geodatabases;they can only be stored in file-based storage solutions. Similar to other ArcGIS file-based storage formats,TINs reside in a folder with a number of interdependent files.

Terrain surfaces

Unique to ArcGIS, the terrain dataset is a collection of participating feature classes that are contained in a feature dataset. Terrains define how multiresolution TIN surfaces are generated on the fly according to a logical indexing of spatially organized source data. The source data is points, breaklines, polygons, and other vector-based measurement data. Since terrains must reside inside a feature dataset, they can only be stored in personal, file, or multiuser geodatabases.

For more detail on terrains, see What is a terrain dataset?

Surface storage option overview

Storage method	Raster surfaces	TIN surfaces	Terrain surfaces
Personal geodatabases	Raster datasets and/or catalogs	No	Terrain dataset inside a feature dataset
File geodatabases	Raster datasets and/or catalogs	No	Terrain dataset inside a feature dataset
ArcSDE geodatabases	Raster datasets and/or catalogs	No	Terrain dataset inside a feature dataset
File-based storage	Many different formats (TIFF, DEM, ESRI Grid, PIX)	ArcGIS TIN format	No