Merge takes into consideration pertinent vessel configuration offsets and the following values, many of which are set in the HIPS Vessel file:
• Navigation
• Gyro - based on the settings in the HIPS Vessel file.
• Dynamic draft - based on the settings in the HIPS Vessel file.
• Smoothed sensor data
• Waterline (if not applied in the SVC process)
• Motion data: Heave, Pitch, and Roll (if not applied in the SVC process)
• Tide or GPS tide
• Delta draft (see Load Delta Draft)
• Refraction coefficients (see Refraction Editor)
• Observed depths
The following operations take place when merging:
• Recorded sensor information is compensated for constant time errors as noted in the vessel file.
• For each time-tagged depth record, the position for the centre of the swath profile is calculated based on the interpolated position fix at that time.
• For each depth record, the position of the sounding is calculated, based on the profile centre position and any gyro/heave/pitch/roll corrections that are appropriate (this is echo sounder system dependent).
• Tide is interpolated and applied to each depth record.
• Draft is applied.
A processed depths file is created for each line. This file contains the final computed geographic position for each depth record.
If any of these offsets or parameters is changed the data must be Merged again.