Validation and Evaluation

This area complements the Initial Planning stage, in that it defines standards for confirming that the actual performance of the PAM system is consistent with the assumptions and predictions made in the planning stage.  Basically, is the system able to achieve the detection range required for the marine mammal species in question?  Some aspects of performance validation take place during the fieldwork; these include measurements of the self-noise of the electronics of the system during the survey, and recording spectra of the background noise levels of the towed system under various circumstances.  Other aspects take place after fieldwork, such as requiring any summary of the PAM operation to document certain performance metrics, and specifying units and formatting for plots depicting these metrics.  It may seem strange that a PAM standard would recommend how to format a plot for a report, but imposing some standards on how PAM summary measurements are presented will facilitate comparisons between different surveys, and aid regulators and independent reviewers in evaluating the adequacy of the operation.

Next: Topics not covered by the standard

3 thoughts on “Validation and Evaluation”

  1. (from Stanley Labak):

    I am not sure if this is the correct location for this, but the following are several other items the may need to be addressed. They include: 1) estimates of the memory needed for each set/type of data to be archived; 2) archiving formats and media(s); 3) validity of the calibration of individual hydrophone in order to get absolute level measurements; 3) flow noise studies for the arrays including breakpoint speeds if available; 4) estimations or measurements of currents and winds to determine the degree which the array is “crabbing” through the water mass, while it is making a correct track over land (i.e., is the array truly directly behind the ship as GPS would indicate or does it stream off at some wind/current driven angle?); 5) how accurately are tow length known? Is there a catenary in the towed array and its tow cable?; 6) etc.

  2. (from Marie Roch, SDSU):

    “Other aspects take place after fieldwork, such as requiring any summary of the PAM operation to document certain performance metrics, and specifying units and formatting for plots depicting these metrics. It may seem strange that a PAM standard would recommend how to format a plot for a report, but imposing some standards on how PAM summary measurements are presented will facilitate comparisons between different surveys, and aid regulators and independent reviewers in evaluating the adequacy of the operation.”

    Seems a bit vague, but might be okay for a standards proposal.

  3. I would also like to bring up the issue of evaluating the rates of missed detection and false detection. Not sure if this fits the scope of the standard.

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