GIS Data Archives - Page 37 of 38

File Formats

July 11, 2013April 21, 2005 by Caitlin Dempsey

Guides to the various file formats and tools for data format conversions. Find conversion utilities to convert from one GIS application to another.

Overview of Elevation Data

July 18, 2013August 27, 2003 by Caitlin Dempsey

Hypsography, topography, elevation, TINS, and contours. There are many different terms for data relating to elevation. This article reviews some of terminology and types of … Read more

Orthophotos and GIS

July 11, 2013April 27, 2003 by Caitlin Dempsey

Aerial photographs play an important role in GIS data acquisition and visualization. First, they help provide a solid visual effect. Many people are more able … Read more

Spatial Data Mining

April 6, 2019February 9, 2003 by Marco Morais

Data mining is the automated process of discovering patterns in data in order to find correlation among different datasets that are unexpected.

USGS Digital Raster Graphics (DRG) Resources

February 24, 2014January 23, 2003 by Caitlin Dempsey

Digital Raster Graphics are created and maintained by the United States Geological Survey (USGS). The maps have been scanned into digital format and contain topographical and survey information. Find resources here to understanding and working with DRGs. The first site to visit is the DRG homepage which contains information about DRGs and how to obtain them.

Hayman Fire, Colorado Image

July 11, 2013June 18, 2002 by Caitlin Dempsey

Image credit: NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team NASA’s Advanced Spaceborne Thermal Emission and Reflection Radiometer (Aster) recently captured images of the Hayman fire burning … Read more

Centers of Population 1790 – 2000

July 18, 2013August 27, 2001 by Caitlin Dempsey

Centers of Population from 1790 – 2000 based on calculations by the US Census.

Jason-1 – Measuring Ocean Topography From Space

April 20, 2014August 25, 2001 by Caitlin Dempsey

Jason-1 is a satellite to be jointly operated by NASA and CNES (Centre National d’Etudes Spatiales), the French space agency. Scheduled for launch no earlier than September 15^th of this year, Jason-1 will work in tandem with TOPEX/Poseidon, a U.S.-French satellite in operation since 1992. TOPEX/Poseidon marked its ninth anniversary in orbit on August 10^th, 2001.

Focus on California – the search for free data

July 11, 2013December 11, 2000 by Caitlin Dempsey

If you are looking for comprehensive and free data for a project, California hosts a wide range of federal, state and local agencies that readily make their data available at no cost. Many of these datasets can be easily downloaded from the Internet. Most can be found in common GIS and CAD formats such as ArcView Shapefiles, ArcInfo export (.e00) or Microstation (.dgn) files.

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