The National Map

USGS The National Map

Public web access to high-quality geospatial data

Selection Principles
The USGS collects, organizes, standardizes, and certifies geological data from partnership organizations and private citizens to include in its National Map project. It claims to take advantage of broadband wireless communication, mass data storage, and geolocation capabilities in personal digital devices (GIS?).

Object Characteristics
There is tons of data that you can view using the Viewer. Examples of layer categories in the interactive Viewer are biology, elevation, geography, imagery, natural hazards, and transportation.

Metadata
Each layer has an associated legend that describes how to read the layer. Contained in the legend is also a link to metadata about the layer. Examples of metadata I found were Indentification informaiton, data quality information, entity and attribute information, reference information. Some layers have better metadata than others.

Audience
The USGS says the significance of the project is in the need for the government to have a common base of information about the Earth's surface. "They use this information as a tool for economic and community development, land and natural resource management, and health and safety services. Federal functions ranging from emergency management and defense to environmental protection rely on this information. Private industry, nongovernmental organizations, and individual citizens also use the same geographic data. Geographic information underpins an increasingly large part of the Nation's economy. One of the lessons learned from the tragedies of September 11, 2001, is that complete and current public domain base geographic information must be immediately available coast to coast and border to border. The National Map will ensure access to this information." So, um, they take themselves pretty seriously. This isn't for the casual Sunday browser.