‘This process is designed to provide the datum shift between the NAVD 88 and NGVD 29 vertical datums at a specified geographic position’

old (2001) slideshow with some good information on NGVD, &c.

GIS gain much of their power from being able to collate and cross-reference many types of data by location.

GIS-Knoppix is a bootable Linux CD with pre-installed GIS software

This document describes an RDF vocabulary for representing WGS84 (world geodesic survey) lat/long/alt positioning.

The latest surveying and GPS technology create a complete GIS of a sunken battleship from the attack on Pearl Harbor

A history of the relation of geology during the first 110 years of the U.S. Geological Survey to the development of public-land, Federal-science, and mapping policies and the development of mineral resources in the United States

from The National Geospatial-Intelligence Agency

GIS database download

Brian McGrath’s impressive, Flash-based historic visualization of Manhattan’s skyscrapers and urban development.

Election officials and activists are turning to geographic information systems and other technology to tailor their approach to finding voters.

“The following tables list NACJD data collections that contain geographic identifiers that could be geocoded for GIS analysis.”

using USGS maps to teach about Lewis & Clark