The Vaisala FS11 is an instrument that uses
forward-scattering technology to measure the amount of scattering of an
infrared beam in a small volume of air between a transmitter and receiver,
resulting in an extrapolated visibility at a set distance out to 5.4 nautical
miles. This is accomplished by the transmitter making continuous infrared light
pulses.
The instrument only captures the visibility at that single
height and location, but not small-scale differences in the air mass, such as
patchy fog or low-lying fog.
Mobile Bay, Alabama is the only other major port in the
nation to install visibility sensors.
“One of the benefits of this new sensor technology is that
it provides good data and consistent results without being dependent on human
observation,” Port of Oakland Acting Maritime Director Jean Banker said. “The
equipment is also designed to be operationally reliable even during the
harshest weather.”
The Nutter terminal is operated by Seaside Transportation
Services and home to Evergreen Marine Corp.
Port of Oakland Chief Wharfinger Chris Peterson called the
installation the culmination of a two-year project that included the port, the
San Francisco Harbor Safety Committee, U.S. Coast Guard Sector San Francisco,
Marine Exchange of SF Bay, NOAA’s National Weather Service Office Monterey and
NOAA’s Center for Operational Oceanographic Products and Services. “Adding this
new capability provides more information to the San Francisco Bar Pilots, the
Coast Guard and other mariners on the bay for safer and more efficient
navigation of ships in difficult and changing weather conditions, in particular
foggy days on the bay,” Peterson said.
Real-time data from the sensors are disseminated on NOAA’s
Center for Operational Oceanographic Products and Services website: http://oceanservice.noaa.gov/websites/supp_coops.html.
