NOAA scientists reach new depths in sea data collection
- By Florence Olsen
- Mar 23, 1997
A crew of systems engineers, normally creatures of the office, sailed this month on the
230-foot hydrographic survey ship Rainier from Seattle to the uncharted coasts around
Their job: to install a four-way Silicon Graphics Inc. Origin2000 data server on the
shipboard network that will receive floods of new information about the ocean bottom.
The National Oceanic and Atmospheric Administration survey ship has six survey
launches, two of them equipped with multibeam sensors that can "completely sweep the
ocean floor," said Cmdr. Jim Gardner, chief of the Systems Support Branch in NOAA's
Hydrographic Surveys Division.
Last year, NOAA completed its first 100 percent bottom-coverage survey. The current
survey off Alaska is the agency's second attempt to cover 100 percent of the ocean bottom,
Until next November, NOAA hydrographers on the Rainier will spend their evenings logged
onto the shipboard network, sifting the day's echo-sounder data.
"I've got six years at sea," said Gardner, who now directs the support
operation from his Commerce Department office in Silver Spring, Md.
Gardner said he is enthused about new sonar and computer technologies that have
transformed hydrography since he came to NOAA in the late 1970s.
"You could spend years in an area trying to find all the least depths," he
Because the new multibeam echo sounders bring back 100 times more data points than
older single-beam sensors, the Rainier needed a 300G RAID Level 5 storage server to
accommodate the extra soundings.
Each multibeam sensor pings 30 times per second as a survey launch moves through the
water, and each ping represents 100 data points, Gardner said.
Along with the Origin2000 data server, Gardner's seaside support staff is installing
Category 5 cabling for a switched 10/100Base-T network to handle the heavier data loads.
The NOAA hydrographers will build up digital terrain models of the ocean floor,
accurate to a half meter. They use the CARIS geographic information system developed by
Universal Systems Ltd. of Fredericton, New Brunswick.
CARIS modules help the hydrographers clean up and process the sonar and side-scan image
data. But Gardner said the hydrographers must learn how to interpret the denser data
before they can develop algorithms that recognize and remove anomalies.
The 27 PCs on the shipboard network access the sonar data and CARIS through X Window
System software from Hummingbird Communications Ltd. of North York, Ontario.
Nearly every stateroom has a PC, "so if a guy is tired of working up in the plot
room, he can go down to his room at night and keep doing his work," Gardner said.
The Rainier does not have enough processing capacity outside the SGI system to handle
the large amounts of data, so the hydrographers will extract from the SGI system only some
data points to represent the sea floor. They will build numerical models in the
Hydrographic Processing System, an in-house application running under Microsoft Windows NT
on an onboard server.
HPS is a 10-year-old patchwork of Hewlett-Packard Co. Basic code ported to Borland
International Inc. dBase 4.0 and mixed with Visual Basic wrappings and bits of MapBasic
and Vertical Mapper from MapInfo Corp. of Troy, N.Y.
The homegrown software makes some beautiful plots and displays, Gardner said.
NOAA takes its mapmaking seriously, because 98 percent of U.S. commerce--by weight--is
waterborne, Gardner said.
As shipbuilders make ships bigger, they reduce the clearance, so it becomes critical to
know the ocean bottom precisely. Every inch of extra draft inside a harbor represents
hundreds of thousands of dollars in cargo on an oil supertanker, for example.
Harbors and channels for big ships are now the only areas that NOAA surveys, because
budget cuts have reduced the number of agency ships and personnel, Gardner said.
NOAA will concentrate its mapping efforts over the coming years on 43,000 square
nautical miles considered critical to U.S. commerce, he said.