# Proportion_occupied

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).

## Algorithm

Where:

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. sv(z) is the sample volume-backscattering coefficient at z.

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

Notes:Svthresh for the Sv variable used for the analysis export is specified by

Minimum thresholdon 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 samplesis not selected, No data samples will be excluded from the calculation.