# Samples

The algorithms on this page are used in analysis calculations for Sv echograms, Single target echograms and Single target echograms with detected fish tracks. Each echogram has a specific data point type which is considered in an algorithm. The data point types are as follows:

 Echogram Data point type Sv Sv samples Single target Single target Single target with detected fish tracks Single target that is the end of a fish track.

Where a "set of samples s" is discussed, the echogram dictates the data point type used for the members of the set.

## Good_samples (no units)

Let A be the set of Sv samples, or single targets or fish tracks s in the analysis domain being considered. Then:

where

 A = the set of Sv samples, single targets, or fish tracks in the analysis domain. Ns = The number of Sv samples, single targets or fish tracks in the analysis domain subject to analysis = Good_samples. = 0 if Sv sample, single target or fish track s is not in the analysis domain, this includes Bad_data_empty_water_samples 1 otherwise, including below threshold data

Notes:

• This forms the denominator in the Sv_mean calculation for single beam data.
• An empty cell is defined as Good_samples = 0.

## Bad_data_no_data_samples

Let A be the set of samples s in the analysis domain being considered. Then:

where

 A = the set of samples in the analysis domain. Nb = The number of bad data (no data) samples in the analysis domain = Bad_data_no_data_samples.  Notes: *The Analysis setting Include volume of no data samples allows no-data samples to contribute to the Thickness_mean. This will affect primary and downstream integration calculations. No-data samples may occur in a number of ways (no-data samples, samples within applied bad data (no data) regions and samples in pings with a bad line status). For further information refer to About analysis domains: Analysis based on regions and samples. *Post Echoview 5.2, no data samples within bad data regions are deemed as bad_data_samples for integration and analysis results. Prior to Echoview 5.2, no data samples within bad data regions were counted as no_data_samples. = 1 if sample s in a Bad data(no data) region and the Analysis setting Apply bad data regions is used 0 otherwise

## Bad_data_empty_water_samples

Let A be the set of samples s in the analysis domain being considered. Then:

where

 A = the set of samples in the analysis domain. Ne = The number of bad data (empty water) samples in the analysis domain = Bad_data_empty_water_samples. = 1 if sample s in a Bad data(empty water) region and the Analysis setting Apply bad data regions is used 0 otherwise

## No_data_samples

Let A be the set of samples s in the analysis domain being considered. Then:

where

 A = the set of samples in the analysis domain. Nn = The number of no data samples in the analysis domain = No_data_samples.  Note: Post Echoview 5.2, no data samples within bad data regions are deemed as bad_data_samples for integration and analysis results. Prior to Echoview 5.2, no data samples within bad data regions were counted as no_data_samples = 1 if sample s is no data. No-data samples may occur in a number of ways (no-data samples, samples within applied bad data (no data) regions and samples in pings with a bad line status). For further information refer to About analysis domains: Analysis based on regions and samples. 0 otherwise

## Samples_Above_Surface_Exclusion

Let A be the set of samples s in the analysis domain being considered. Then:

where

 A = the set of samples s in the analysis domain. NSamples_Above_Surface_Exclusion = The number of samples above the Exclude above line in the analysis domain = Samples_Above_Surface_Exclusion The Exclude above line is specified under the Exclusions and Analysis section on the Analysis page of the Variable Properties dialog box. = 1 if sample s is above the Exclude above line 0 otherwise

## Samples_Below_Bottom_Exclusion

Let A be the set of samples s in the analysis domain being considered. Then:

where

 A = the set of samples s in the analysis domain. NSamples_Below_Bottom_Exclusion = The number of samples above the Exclude below line in the analysis domain = Samples_Below_Bottom_Exclusion The Exclude below line is specified under the Exclusions and Analysis section on the Analysis page of the Variable Properties dialog box. = 1 if sample s is above the Exclude below line 0 otherwise

## Samples_In_Domain

NSamples_In_Domain = Ns + Nb + Ne+ Nn + NSamples_Above_Surface_Exclusion + NSample_Below_Bottom_Exclusion

where

 NSamples _In_Domain = the number of samples in the analysis domain = Samples_In_Domain Ns = the number of samples in the analysis domain subject to analysis = Good_samples. See also Good_samples algorithm. Nb = the number of Bad data (no data) samples in the analysis domain = Bad_data_no_data_samples.  Note: Post Echoview 5.2, no data samples within bad data regions are deemed as bad_data_samples for integration and analysis results. Prior to Echoview 5.2, no data samples within bad data regions were counted as no_data_samples. See also Bad_data_(no data) samples algorithm. Ne = the number of Bad data (empty water) samples in the analysis domain = Bad_data_empty_water_samples. See also Bad data (empty water) algorithm. Nn = the number of no data samples in the analysis domain = No_data_samples.  Note: Post Echoview 5.2, no data samples within bad data regions are deemed as bad_data_samples for integration and analysis results. Prior to Echoview 5.2, no data samples within bad data regions were counted as no_data_samples. See also No_data_samples algorithm. NSamples_above_surface_exclusion = The number of samples above the Exclude above line in the analysis domain = Samples_Above_Surface_Exclusion The Exclude above line is specified under the Exclusions and Analysis section on the Analysis page of the Variable Properties dialog box. NSamples_below_bottom_exclusion = The number of samples above the Exclude below line in the analysis domain = Samples_Below_Bottom_Exclusion The Exclude below line is specified under the Exclusions and Analysis section on the Analysis page of the Variable Properties dialog box. See also Samples_Below_Bottom_Exclusion algorithm.

#### Note:

The total number of samples in an analysis domain which are not above an exclude-above line or below an exclude-below line can be calculated as:

Good_samples + Bad_data_no_data_samples + Bad_data_empty_water_samples + No_data_samples

A count of the total number of samples excluded is not currently available.