About frequency distribution
The ME70 Multibeam scientific echo sounder employ Frequency Rotated Directive Transmission (FRDT) to achieve the performance requested for fishery research applications. This means that each individual beam in the acoustic fan uses its own centre frequency to obtain two-way side lobe suppression.
The frequency allocated to each beam can be controlled as one of three alternative modes:
•  Linear mode
•  Optimized mode
•  Manual mode
You can select this mode using the Frequency/Beam Spacing parameter located on the Frequency Band page in the Beam Mode dialog box.