Getting the Map
into the Computer

GIS data can be:

GIS Data Conversion

GEOCODING

GEOCODING LEAVES A “STAMP” ON DATA

Geocoding methods for maps

Digitizing

The Digitizing Tablet

Selecting points to digitize

Some common digitizing errors

Scanning

Scanning

Scanning example

Field data collection

GPS Attribute Data

Finding Existing Map Data

Existing Map Data

Commercial vendors

Federal Data Agencies

National Spatial Data Infrastructure

National Spatial Data Clearinghouse

USGS: National Mapping

US GeoData
ftp access to DEM, DLG, etc.

Examples of USGS Digital Raster Data

Examples of USGS Digital Vector Data

US GeoData Download Statistics

National Mapping Information

USGS Earth Explorer

"Distributed active archive center"

CORONA
(Declassified Spy Satellite Images)
Goleta, CA, 1967 Image

U.S. National Atlas Map Layers Download

The USGS National Map Project

NASA’s Shuttle Radar Topography Mission

U.S. Bureau of the Census

NOAA


Weather, climate, oceanographic, and other data—available as ArcView grids!

California Spatial Information Library

Other Sources for Free or Cheap Downloadable GIS Data?

SDTS:
Spatial Data
Transfer Standards