Proportion_occupied is an analysis export variable available in exported integration analyses.

It reports the proportion of the water column with Sv above a threshold; considers all samples of the domain. The exported Proportion_occupied is equivalent to the 'Proportion occupied' as used by Urmy et al (2012).


Proportion occupied equation


Pocc is the Proportion_occupied (unitless).
H is the height of the water column.
z is the depth (m) of a sample in the analysis domain given that the sv of the sample is greater than the threshold.

is the sample volume-backscattering coefficient at z.

Sv (dB re 1m-1) is the (mean) Volume backscattering strength of the sample at z.


Svthresh for the Sv variable used for the analysis export is specified by Minimum threshold on the Data page of the Variable Properties dialog box.

Thresholded Sv (dB) values are handled as 0 in the linear domain.

When the Analysis setting Include the volume of no-data samples is not selected, No data samples will be excluded from the calculation.

See also

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