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Geospatial Data: Home

This guide describes how to find and use the DREAM Lab's spatial data, as well as data that is available freely online.


Use this guide to help identify and use spatial data in the library's collections or on the web.  Pages include how-to sheets on common GIS tasks, pointers for frequently requested data, and ...


Table of Contents:

Don't see what you need?  Contact the DREAM Lab directly:

(805) 893-8946

What is GIS data?

In order to use GIS software, you have to have GIS data. This guide shows you the different GIS file formats and types and provides you with a number of online sources for accessing data.

Data Formats and Manipulation

Vector: discrete coordinates and surfaces represented as points, lines, or polygons (areas). File formats: shapefiles, coverages, KMLs

Vector file of California

Raster: continuous surface divided into grid cells of equal size. File formats: Geotiff, tiff, JPG, MrSID

Tables: data tables that contain records for places that can be converted by plotting coordinates or joining identifiers to a vector file. File formats: delimited text files, spreadsheets (xls), data tables


Geodatabase: collection of vectors, rasters, and tables in a database file. File formats (desktop): Access mdbs, SQLite

Please note:  GIS files are often distributed in compressed file formats--in other words, inside of containers holding several data files. Common formats you may encounter include ZIP, 7z, and TAR.  E00 is an ESRI file format used to exchange coverages.  Windows and Macintosh operating systems can handle many of these formats.  There are plenty of free tools available to handle most other cases.