Data Acquisition and Processing Report (DAPR) - Center for Coastal ...

The speed of sound through the water was determined by a minimum of one cast
every four hours during multibeam acquisition. The primary CTD was checked against
the secondary unit and was in general agreement. Each unit had been calibrated prior to
use for this survey; refer to Appendix D for the SBE calibration reports.
Assessment of Patch Test and Results
The Hydrographer believes that the values of the latency, pitch, roll and gyro
coupled with a thorough review of the patch test lines in Caris HIPS HDCS editor,
adequately meet the alignment requirements for both systems. The following image
represents an area of feature alignment that was collected with a combination of six lines
of multibeam data from both sonar systems.
Fig 6: Feature mapped with the EM1002 & 7125 multibeam system
Assessment of Dynamic and Static Draft
Dynamic draft values for the NANCY FOSTER were performed during the Sea
Acceptance Test (SAT) offshore of Charleston, South Carolina in March of 2006.
Representatives from the NOAA Aviation and Marine Operations (NMAO) performed
the survey and evaluated the results. Four-RPM levels were used to determine the
dynamic draft: 790, 1000, 1300 and 1600. The observed changes in draft were
negligible, with a maximum corrector of 0.041m. The values of the dynamic draft were
entered into the vessel configuration files and were applied during the merge process.
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