Saturday, December 11, 2010

NOAA rescues Civil War-era coastal charts, now available online

From GCN

A collection of nearly 400 Civil War era charts once again is available to the public, now in an
online searchable database hosted by the National Oceanic and Atmospheric Administration, providing a historical record of U.S. terrain, ports and coasts as they were from 1861 to 1865.

“The agency has an amazing legacy,” NOAA Chief Geographer Meredith Westington said.
“We’re talking about 200 years’ worth of history.”

NOAA, together with the Library of Congress, still is in the process of digitally scanning 28,000 coastal and geodetic survey charts, and plans to launch a new version of the historical Web site in February, with a geographic information system that will enable searches of the collection using map coordinates.

The project is more than simply digitizing existing collections, Westington said. “It was more of a rescue effort” when it began in 1995 at an off-site printing facility used by NOAA. “They were closing their doors and they were going to throw out thousands of things.”

NOAA was notified and began gathering the documents. “We were pulling things from map drawers without knowing in advance what they were. Most of this stuff should have already been in the National Archives anyway.”

The online Civil War collection was launched in October in anticipation of the 2011-2015 sesquicentennial of the war and has received about 6,000 new hits since going up.
It is part of a larger historical collection that contains more than 21,000 maps and charts dating from 1747 to 2001.
It includes 394 maps and nautical charts, as well as documents including Notes on the Coast of the United States, secret records covering the coast from the Delaware Bay to the Mississippi Sound on the Gulf Coast.
The notes include detailed handwritten descriptions of ports and navigable rivers, along with sailing directions with positions of hazards, lights, beacons and buoys.

“The new collection is one of our more popular pages at the moment,” said Westington.
“We’ve received nearly as many questions about our historical maps and charts as our latest-edition nautical charts.”

A word of caution: The historical charts are marked “not for navigational use.
If you plan sailing through Charleston or Baltimore Harbor, use an up-to-date chart.

The process of digitizing historical material for preservation and online access is continuing
The equipment used has varied since 1995, when the metadata was collected by hand.
Much of that collection work now is automated, and for the past five years most of the scanning is being done by contractors, primarily HOV Services in Beltsville, Md., which provides document imaging and management services.

Current requirements call for the scanning to be done on a Crystal XL 42-inch wide format color scanner from Contex A/S of Denmark, in an uncompressed TIFF format at a minimum resolution of 300 dpi, in 24-bit color.
Information collected for each chart includes scan file name, date and resolution; chart title, edition and date; the dimensions of the original paper and the map on it; and the corner latitude and longitude.

The data is recorded using Microsoft Access and transferred to a larger PostgreSQL open-source object relational database.
PostGIS adds support for geographic objects to the database, spatially enabling the PostgreSQL server for geographic information systems.

When the GIS tool is enabled on the NOAA Web site, users will be able to search by coordinates or drill down from a reference map to find the desired documents, rather than using a word search in the collections.

Links :
  • NOAA : How the U.S. Coast Survey Helped ‘Chart a More Perfect Union’

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