Single target detection algorithms

Echoview offers single target detection algorithms for single beam, split beam and dual beam data and methods that are suitable for source data with and without embedded TVG range correction. Generally, Single target detection Method 1 algorithms are suitable for data with embedded TVG range correction. Method 2 algorithms are generally suitable for source data where the TVG range correction has not been applied.

The following table can help you select a suitable single target detection algorithm method:

Data

Single target detection Method 1

Single target detection Method 2

Simrad Ex500 sample data:

  • W, P datagrams

Recommended.

Not recommended.

However, it is possible to use this combination under the following conditions.

Only if TVG range correction is not applied to the input TS variable, or if any applied correction is accounted for in the Method 2 operator settings.*

Simrad Ex60 data:

  • TS raw pings
  • W, P datagrams logged to Ex500 format

Not recommended.

However, it is possible to use this combination under the following condition.

Only if a TVG range correction is applied to the input TS variable.**

Recommended.

Simrad EK80 data:

  • Data logged under the Simrad EK80 CW configuration is handled as for Simrad Ex60 data.
  • TS pulse compressed complex wideband pings
  • angular position pulse compressed wideband pings

Not available.

Recommended.

A wideband method is based on single target detection method 2.

BioSonics:

  • DT
  • DT-X

Not recommended.*** 

Recommended.

Sonic formats

Not recommended.***

Recommended.

HAC format and text data formats

Dependent on the original data source.

Recommended with the condition:

Only if TVG range correction has been applied to the input TS variable.****

Dependent on the original data source.

Recommended with the condition:

Only if TVG range correction is not applied to the input TS variable.****

Raw data from other echosounders

Not recommended.***

Recommended.

* EK500 TVG range correction is applied by default but can be turned off for TS W datagrams from an Ex500. It is embedded in TS P datagrams from an Ex500.

** EK60 TVG range correction is turned off by default for TS raw pings and TS W datagrams from an Ex60. It can optionally be applied to those datagrams. It is not embedded in TS P datagrams from an Ex60, and cannot be applied in Echoview.

*** Echoview does not allow for application of TVG range correction in these TS data. TVG range correction is required for use of the Method 1 algorithm with BioSonics data, Sonic data or other raw data formats where TVG is calculated and applied by Echoview.
Note: The error introduced by using no range correction with the single target detection - dual beam (method 1) algorithm is of the same order as that introduced by using the single target detection (method 1) algorithm.

**** This correction cannot be applied in Echoview, but it is possible that a correction has already been embedded in the input TS data prior to its import to Echoview.

Notes:

  1. The Method 1 algorithm is the algorithm implemented+ in Echoview for Ex500 echosounders and should yield an almost perfect match with E datagrams from an Ex500.
  2. The Method 2 algorithm is based on the algorithm implemented in the Ex60 echosounders and should yield a good match with E datagrams from an Ex60.
  3. With appropriate TVG range corrections the Method 1 and 2 algorithms are valid with data from other supported echosounders#.
  4. A TVG range correction setting for the Biosonics and Sonic data formats is included in Echoview 4.40 and higher.
  5. A single target detection - dual beam method 2 algorithm is included in Echoview 4.40 and higher.

+Soule M., Barange M., Solli H. and Hampton I. (1997) Performance of a new phase algorithm for discriminating between single and overlapping echoes in a split-beam echosounder. ICES Journal of Marine Science, 54: 934-938.

#There is a choice of beam compensation model in Echoview. Please contact (support@echoview.com) if you any questions regarding the beam compensation for your data.

Algorithms

The table below lists the single target detection operators that are available in Echoview. The single beam and split beam (method 2) and Wideband algorithms use a SoundSpeedProfile when it is available.

Note: For detailed information about the algorithm applied by an operator click the relevant operator.

Operator

Description

Single beam (method 1)

This operator detects single targets using the algorithm implemented by Simrad in the Ex500 series of echosounders.

Single beam (method 2)

This operator detects single targets using Echoview Software's understanding of the algorithm implemented by Simrad in the Ex60 series of echosounders.

Split beam (method 1)

This operator detects single targets using a modified version of the single target detection single beam (method 1) algorithm that applies beam compensation estimates (based on split-beam angle data) to the peak selection criteria.

Split beam (method 2)

This operator detects single targets using a modified version of the single target detection single beam (method 2) algorithm that applies beam compensation estimates (based on split-beam angle data) to the peak selection criteria.

Dual beam (method 1)

This operator detects single targets using a modified version of the single target detection single beam (method 1) algorithm that applies beam compensation estimates (based on difference between a narrow beam and wide beam signal) to the peak selection criteria.

Dual beam (method 2)

This operator detects single targets using a modified version of the single target detection single beam (method 2) algorithm that applies beam compensation estimates (based on difference between a narrow beam and wide beam signal) to the peak selection criteria.

Wideband This operator detects single targets using an algorithm that applies beam compensation estimates to the peak selection criteria. The operands are pulse compressed wideband Complex TS and angular position variables.
Single target detection - Furuno FCV-30 This operator outputs FCV-30 single targets found in processed compensated TS data produced by
the Furuno FCV-30 sounder.

Warning: The single target detection operators assume that the data are of sufficient resolution to define the echo envelope of the target. Click the required operator in the table above for more information.

Notes:

Echosounder manufacturers algorithms (Simrad, BioSonics and Sonic)

The (method 1) single target detection algorithms have been based on references cited that describe improvements on the algorithm applied by Simrad's Ex500 echosounder.

The (method 2) single target detection algorithms have been based on Echoview Software's understanding of the algorithm applied by Simrad's Ex60 echosounder.

The dual beam single target detection algorithm implements the BioSonics beam compensation algorithm for dual beam echosounders.

The algorithm used by Sonic in the KFC3000 in their post-processing software is not implemented in Echoview.

See also

About Single target detection
Single target pulse properties

Echoview and Simrad algorithms

Simrad and Echoview single target detection terminology
Beam compensation

Footnote:

1TSAN is the name of the TS and SV analysis software manufactured by Sonic corp.