|
|
|
Where:
The mean thickness of an analysis domain A defined as follows.
Let Ap be the set of pings p in the analysis domain, then:
Where:
|
T
|
= the mean thickness of the domain, Thickness_mean (m) |
|
Np
|
= the number of pings in the analysis domain The value for Np is affected when For more information refer to About samples and echo integration: Calculations. |
| tp | = the thickness of ping p (m), calculated: |
Note: There can be a difference in the thickness_mean of Sv echograms and single target echograms. The Sv algorithm is based on analysed samples in the domain. The single target algorithm is based on exact range calculations in the domain.
 |
 |
Where:
|
As
|
= set of samples s in ping p in the analysis domain. | ||
|
Dtp
|
= the thickness of one sample - that is, the sample spacing for ping p (m). | ||
 |
= |  |
0 if sample s is excluded from the analysis of the domain. |
| 1 otherwise, including below threshold data. | |||
 |
|
Where:
|
NR
|
= the number of boundaries crossing the ping (-). See illustration below. | ||
|
Ri
|
= The range of boundary i in the ping (m). See illustration below. |
||
 |
= | |
0 if the interval Ri R < Ri+1 is excluded from analysis. |
| 1 otherwise | |||
Note: If an analysis domain contains no single targets, no value of thickness mean is calculated or exported. On the other hand, when an analysis domain does contain at least one single target, contributions to tp are included from intervals that are included in analysis but have no single targets within the interval.
An illustration of boundaries in a ping, for the purposes of calculating tp. The red hatching is the analysis-hatching.
Height_mean is the projection of thickness_mean onto the vertical axis taking transducer geometry into account. For a vertically mounted transducer pointing directly downwards, Height_mean and Thickness_mean are equal.
About analysis domains
About transducer geometry
About depth and range
Samples
About integration
About samples and integration
About no data
Thickness mean and Height mean
ABC and NASC
