Raw variables derived from Humminbird sonar data files

This page describes the variables that Echoview can derive from Humminbird data files.

.DAT and .SON files recorded by Humminbird Helix, Solix, Apex, and 900/1100 series instruments

Not all variables will be present in all datasets. The specific variables derived depend on the transducers and settings used to record the file.

Notes:

Humminbird writes GPS in every .SON file; Echoview reads a fix for every ping. With multiple .SON files this can create duplicate fixes that affect distance-based calculations. If this is encountered, export Position GPS fixes to CSV, remove duplicates, then add the cleaned CSV file to a second fileset and use it as the position source for your Platform object.
Acoustic samples are stored as 8-bit intensities (values 0–255).
Values are imported as unspecified dB. This reflects that Humminbird files store data in a logarithmic scale proportional to signal strength, but not calibrated Sv or TS.
These variables are suitable for qualitative display and detection, but not quantitative analysis without further conversion.
If required, values can be reinterpreted with linear units using the Type conversion operator, then converted back into dB space. However, because Humminbird data are not designed for calibrated use, results may vary.