Frequently Accessed Data

Frequently Accessed Data Layers

A Collection of commonly used GIS datasets for California. This collection includes datasets formally offered by the Teale Data Center.  Most data are maintained in an Albers projection to enable overlay and integration functions, and are organized by theme.

Digital Orthophoto Quadrangle GeoTiff (DOQQ)

Orthophotos combine the image characteristics of a photograph with the geometric qualities of a map. The primary digital orthophotoquad (DOQ) is a 1-meter ground resolution, quarter-quadrangle (3.75-minutes of latitude by 3.75-minutes of longitude) image cast on the Universal Transverse Mercator Projection (UTM) on the North American Datum of 1983 (NAD83). DOQ's serve a variety of purposes, from interim maps to field references for earth science investigations and analysis. The DOQ is useful as a layer of a geographic information system and as a tool for revision of digital line graphs and topographic maps.

California Digital Raster Graphics

The Digital Raster Graphic (DRG) is a raster image of a scanned USGS topographic map including the collar information. The source maps for DRGs were georeferenced to the UTM grid, but DRG images for California are available in Albers equal area projection (see the projection information). A DRG is useful as a source or background layer in a GIS, as a means to perform quality assurance on other digital products, and as a source for the collection and revision of DLG data. DRG's can also be merged with other digital data, e.g. DEM's or DOQ's, to produce a hybrid digital file.

California Landsat Images

This product was created by the U.S. Geological Survey (USGS) and contains Landsat data files in Geographic Tagged Image-File Format (GeoTIFF). The Landsat 1, 2, and 3 satellites carried the multispectral scanner (MSS) sensors; the Landsat 4 and 5 satellites carries both the MSS and the thematic mapper (TM) sensors; and the Landsat-7 satellite carries the enhanced thematic mapper plus (ETM+) sensor. All three sensors are a part of an ongoing mission to provide quality remote sensing data in support of research and applications activities. This collection contains Landsat images for the State of California, as part of the CalView project. The images have all been reprojected to the California Albers Projection, NAD 83 datum, and provided in GeoTiff format.

Caifornia Spot Imagery

1998-2000 SPOTView Panchromatic Imagery The State of California has purchased statewide 10-meter, black and white satellite imagery (SPOTView images from 1998 through 2000) from SPOT Image Corporation, and a license to distribute imagery to State of California agencies, local government, federal government partners, universities, K through 12, and the provincial government of Baja California, Mexico. We apologize, but our license agreement with SPOT Image Corporation does not include distribution to the general public. Therefore, this collection is not online for direct download, but can be ordered on CDROM.

CaSIL as a File System

You may use FTP or HTTP to access the CaSIL data holdings and treat them as one big file system. The collections are organized by contributing agency. Please see the CaSIL User's Guide for more information on how to take advantage of this access method.