Bad-weather calibration of split-beam echo sounder systems
Original version
This report is not to be cited without prior reference to the authorAbstract
A condition for standard-target calibration is stability of the sonar
platform and target rig. This condition cannot always be met, nor need it be
when the transducer has a split-beam function. Since the position of the
target can be known even when it is moving, the beam pattern can thus be
removed from the measurement, allowing direct sensing of the target's
backscattering cross section whenever the target is in the beam. The
calibration can therefore be performed when the target is off-axis or moving.