About scanning
Echoview accepts multibeam data acquired under a number of platform and echosounder scanning configurations. These are:
Each of these scanning configurations provides access to different school detection and integration algorithms in Echoview.
Cruise scanning
Data is collected from a moving platform with a supported transducer geometry and unvarying tilt and bearing angles (where supported). See About ping modes for supported transducer geometries. This is supported for all ping modes in Echoview.
The school detection algorithm and integration algorithm available will depend upon the ping mode.
Instrument scanning
Data is collected from a stationary platform using a scanning sonar with a supported transducer geometry by varying the tilt or bearing angle. This is supported for H-mode, V-mode and S-mode data only in Echoview.
The school detection algorithm and integration algorithm available will depend upon the ping mode.
Target-locked scanning
Data is collected from a stationary or moving platform logging V-mode and H-mode data.
You must associate the H-mode and V-mode data by selecting a Target-locked variable on the Data page of the Variable properties dialog box before it is considered to be target-locked in Echoview. Only then will Echoview attempt to identify target-locked ping pairs in these two variables.
There are two ways of collecting and representing target-locked data. Each ping has a property, ping group, which is used to distinguish these:
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simultaneous |
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The V-mode and H-mode ping are at the exact same time. Each ping has a ping group of 0. A target-locked ping pair consists of one H-mode and one V-mode ping with exactly the same time stamp. |
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alternate |
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The V-mode and H-mode pings alternate, first one then the other. Each ping has a ping group of 1 or 2. Ping group 1 identifies the first ping in a target-locked ping pair and ping group 2 the second ping in a target locked ping pair. A target-locked ping pair is one ping with ping group 1 (the first ping) and one following it with ping group 2 (the second ping). The second ping must be before the next ping in its paired variable, and the first ping must be after the previous ping in its paired variable. |
The target-locked scanning algorithms for school detection and integration are available for this data.
Note: The H-mode and the V-mode variable each have their own variable properties. If you specify a Target-locked variable on the H-mode variable properties then you can use the target-locked school detection and integration algorithms on the H-mode variable. You cannot use target-locked algorithms on the V-mode variable in this case. You can however specify a Target-locked variable on the V-mode variable properties to do so, either instead of, or in addition to specifying one on the H-mode variable.
See also
About school detection
About integration
About school detection algorithms
About integration algorithms