A General Guide for Deriving Abundance Estimates from Hydroacoustic Data





Correction of incorrect settings

It is important to remember which system and data collection settings may be changed in post-processing.  Table 6 is a summary of system settings and collection settings and whether they can be modified in post-processing.


Table 6.  Modification status for system and collection settings.



Not modifiable

Simrad and Biosonics



Transducer gain


Pulse duration


Ping rate


Raw data depth/range


File size


Transducer depth


Collection thresholds1


Sound speed







Simrad only



Sa correction


Power setting


Equivalent beam angle


3 dB angle


Bottom backstep





Biosonics only



Threshold model


1 does not apply to Simrad raw data