Data acquisition, management, quality control and processing for acoustic surveys: 
                                Methods of best practice

                                        Tim Pauly


                      Hydroacoustics, Australian Antarctic Division
                      Channel Highway, Kingston, Tasmania 7004
                              Email: tim_pau@antdiv.gov.au


     The  Australian Antarctic  Division has  a long  history of  conducting acoustic 
surveys  in  Antarctica,  starting  in  1980  with  The  First  International  Biomass 
EXperiment  (FIBEX).   During  the period  29th  January  to 21st  March  1996 we 
conducted an Antarctic  krill biomass survey covering and  area of 873,000 km2 (80E 
and 150E).
    Acoustic data was logged using operating frequencies of 200, 120, 38 and 12 kHz 
with hull mounted transducers  and a 120kHz towed body.  Ping echogram  data (700 
pixels)  were continuously  logged  for all  frequencies  throughout  the survey.    In 
conjunction with the  acoustic data 145 CDT casts,  69 routine (pre-determined sites) 
and 102 target trawls (trawls directed at acoustic target) were made.
    The biomass estimate  from the 120 kHz data and  regular trawls was calculated 
and presented to and accepted  by the Working Group for Ecosystem Monitoring and 
Management  (WE-GEMM) of  the  Commission for  the  Conservation of  Antarctic 
Marine Living  Resources (CCAMLR) in less  than 4 months from  the completion of 
the voyage.  Both temperate  (Port Arthur  Australia) and  cold water  calibrations ( 
Casey  Base Antarctica)  were conducted.  The  survey data  was  logged, managed, 
quality controlled and processed using a suit of software routines called ECHO which 
was  jointly  developed  by  the  Antarctic  Division  and  Commonwealth  Industrial 
Research Organisation (CSIRO) in Australia.
    Final  analysis  and all  algorithm  development  was conducted  using  Mathcad   
work  sheets  developed  in  house.   This  work  outlines  the  methods  used  for: 
conducting the survey; editing the acoustic  ecohgram, positional, and vessel log data; 
hydrographic  measurements  and  corrections;   conducting  and  processing  trawls; 
reducing the data to transect averages and estimating the biomass.