The 'Okeanos Explorer' is conducting mapping operation in the Western North Atlantic as part of the annual ship shakedown.
Multibeam and singlebeam mapping operations are being conducted 24/7 between Rhode Island and the U.S.-Canadian territorial boundary, while sub-bottom profile mapping is being conducted each day between the hours of 1000 and 1800 throughout the March 18, 2013, to April 5, 2013 cruise.
Research vessels conduct annual ship shakedown tests to perform at-sea testing of all scientific and shipboard systems following any significant period of inactivity and after major changes or upgrades to systems. Shakedown cruises are essential to a successful field season, and NOAA Ship Okeanos Explorer conducts one every year.
Multibean Patch Test
As part of the at-sea testing, NOAA conduct a system calibration to quantify the accuracy, precision, and alignment of the multibeam sonar. The calibration includes determination of residual biases in roll, pitch, heading, and navigation timing error. This procedure, commonly referred to as a “patch test,” is performed by acquiring data that will highlight only one bias parameter at a time. Generally two lines of data must be acquired to resolve each bias. Vessel speed, direction and/or seafloor slope will be specified for each line.
Ship shakedown cruises are also used by the ship to provided refresher training and safety stand-down for all crewmembers and to run all of the ship's equipment after sitting alongside a dock for several months during the offseason, typically in winter.
Ships typically take this time to perform safety drills and routine maintenance on major equipment including main engines, stern and bow thrusters, dynamic positioning system, fast rescue boats, cranes, and even galley equipment like refrigerators and ovens. All of this equipment is essential to a successful field season and must be sea tested before heading to distant ports of call for several months.