R2Sonic 2026, Operation Manual, Page: 74 / 254

Page 74 of 254
Version 6.3 Rev r012
Date 05-11-2022
Part No. 96000001
A more technical way to look at this is the change over from equidistant to equiangular occurs when
the outer beam grazing angle is 80° or greater. This is based on the below equation:
(Swath Width / 2) + Head tilt + Sector rotate = grazing angle of the outermost beam
Figure 64: Bottom Sampling Modes
5.6.6.1 Dual/Quad Mode
The Dual/Quad bottom sampling modes can be used with both equiangular and equidistant
sampling. The modes work by spatially distributing the acrosstrack bottom sampling, ping by ping.
The beam is slightly repositioned, in the acrosstrack direction, with each ping. This mode was
developed for ROV/AUV survey operations.
The Dual/Quad mode will work at all speeds; however , it is at slower speeds, that the Dual or Quad
modes will be more evident.
Beam Repositioning Angle = [SectorCoverage / (256-1)] / n
Where:
n = 1 for Normal Mode
n = 2 for Double (or Dual) Mode
n = 4 for Quad Mode
The Dual/Quad mode requires 16-May-2013 head firmware and 17-Oct-2013 GUI or more recent.
All firmware from Head$16-may-2013-03-58-29 will have this feature available. All GUIs, from
17Oct2013 and newer, will support the Dual/Quad mode.