3. Data Reduction Procedures

• Data is processed in batches with a FORTRAN program on a Windows PC.
• Groups of zero-point and carriage run raw data files are read.
• Analog voltages are scaled to engineering units and the zero-point correction is computed.
• For the static drift tests, average values of force and moment are computed from the time histories.
• For the dynamic tests, the prime frequency of the motion is computed with a fast-Fourier transform, followed by computation of a 6th-order FS expansion of the forces and moment, followed by a correction to Fx.
• Additionally, the mount-mass effect is computed and subtracted from the dynamic data.
• For the free condition cases, the 6DOF motion of the ship model is analyzed as per the forces and moment harmonic analysis.
• All periodic data is expressed and output through one PMM cycle.
• Finally, the maneuvering coefficients are computed as the last data reduction step.