ACOUSTICS UNPACKED

A General Guide for Deriving Abundance Estimates from Hydroacoustic Data

 

 

 

 

Data Processing

Data collection parameters are set to acquire data that can be used for a variety of purposes, whereas post-processing parameters and techniques are often optimized for single species.  In other words:

  • data collection attempts to maximize the detection probability for a wide variety of organisms, while
  • post-processing attempts to maximize the detection probability for the species of interest and minimize the detection probability for all other organisms (NMFS SOP).
  •  

    File preparation

  • Data files
  • System and environmental settings
  • Bottom detection
  • Surface exclusion zone
  • Bottom exclusion zone
  • Noise removal
  • Single echo detection

    Analysis bin selection

  • Vertical
  • Horizontal
  • Great Lakes analytic bin sizes
  • Separating groups of interest

  • Spatial or temporal separation
  • Target strength
  • Partitioning trawl catches
  • Thresholds
  • Challenges and developing approaches
  • File exports