NIMA digitizes ocean maps
- By Gregory Slabodkin
- Oct 26, 1998
Digital charts from the National Imagery and Mapping Agency will eventually replace the
paper charts the Navy uses to navigate the worlds waterways.
NIMAs Digital Nautical Chart is a vector-based database containing all the
navigating data, including water depths, currents, reefs, shoals and shorelines, that
captains need when steering a ship. The electronic data is captured from NIMA and National
Oceanic and Atmospheric Administration paper charts and digitized so that it works with
digital marine navigation systems.
Most oceans and coastal waters will be included in the DNCs final version. The
worldwide database is divided into 29 regions, each on an individual CD-ROM.
NIMA by 2000 will transfer 5,000 paper charts onto 29 CD-ROMs, each designating a
section of ocean. The agency so far has completed 54 percent of the database, or about
2,700 charts. The database, which details most of the oceans in the northern hemisphere,
is stored on 20 CD-ROMS.
DNC right now is only available to the military, primarily the Navy, U.S. Coast
Guard and their contractors, said Walter Kozak, NIMAs DNC requirements
manager. He is assigned to the Navy Customer Support Office in Reston, Va.
The software will eventually be released for use by the public.
Its not available to the public yet, Kozak said. But we intend
to make a U.S. waters-only version of DNC commercially available by June 1999.
Ultimately, by 2002, DNC will cover all areas of commercial shipping activity, NIMA
DNC will let skippers on commercial ships move cargo more efficiently through ports
around the world. The more accurate navigation system will reduce the chances of ship
collisions and collateral damage such as oil spills, reef groundings and other
environmental damage, NIMA officials said.
NIMAs Digital Nautical Chart is considered by many [to be] the greatest
advance in safety at sea since the introduction of radar, said Vice President Al
Gore, at the National Oceans Conference in Monterey, Calif., this summer.
When DNC is publicly released it will be available for purchase commercially. But
Defense Department users will not have to pay for the system.
The Navys goal is for all its ships to use electronic nautical charts by 2007,
but the service may beat that deadline.
NIMA has sent its Full Utility Navigation Display software to 400 Navy ships so
captains and navigation officers can learn about the system. The Navy has built electronic
chart display systems on the ships to accommodate the system.
The database is only available on CD-ROM to the military because there are
sensitivities we have to consider, Kozak said. The baseline information for
waters outside of the United States comes from foreign governments that are not
comfortable with us making DNC available. NIMA policymakers are working on how to find a
way around that problem right now.
NIMA is also developing a maintenance system for keeping the database current and
supporting safe navigation, Kozak said. Navy ships now use DNC to mark their positions but
still rely on paper charts for primary navigation, he said.
DNC will replace the traditional charts once the system has an interface with Navy
navigation systems and can be continually updated, Kozak said.
DNC will operate with the Defense Departments Global Positioning System, a
satellite navigation system that is accurate up to a few square yards. Ships will have an
accurate fix on their positions around the clock in real time, Kozak said.
When DNC is displayed on a computer screen or an electronic chart display
information system, you can take a GPS receiver or its position and interface it with the
electronic chart, Kozak said. GPS will give you the ships continuous
position on the electronic chart as opposed to a paper chart where you have to use a
pencil or pen to mark the position every few minutes.
NIMA has validated a direct chart reader that allows data from the DNC database to be
displayed in the vector product format. Software from Sperry Marine Inc. of
Charlottesville, Va., running under Microsoft Windows NT takes data from a CD-ROM and
produces a color image of the nautical chart.
The database has 12 layersnavigational aids, cultural landmarks, earth cover,
environment, hydrography, inland waterways, land cover, limits, obstructions, port
facilities, relief and data quality. DNC lets users access the layered navigational
features that are of immediate importance to them.
The Navy demonstrated DNC last month aboard the USS Constitution in Boston Harbor. The
Navy chose its oldest commissioned ship to highlight the state-of-the-art navigating