Koden CVS-702D, Основное руководство по эксплуатации

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Chapter 2 Basic operation CVS-702D
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2.5.2 To erase the weak response from dust and plankton, etc.
To erase the weak response from dust and microbes such as plankton in seawater, there are
following 4 methods:
1. Setting TVG
2. Shortening pulse length and narrowing frequency bandwidth
3. Setting [Color Erase] function
4. Setting [Noise Reduction] function (See “2.5.3 To reduce noise”, p 2-83)
When TVG is effective:
In order to erase the response from dust and plankton at shallow depth of the displayed
screen, setting TVG is effective.
TVG can be set in two ways, [Optimized TVG] and [Manual TVG].
In the case of setting in [Optimized TVG], the images are clear with less interference noise
down to water depth of approximately 100 m.
As for the setting of [Optimized TVG], see “To use of optimized TVG”, p 2 - 57.
By setting [Manual TVG], noise reduction setting is possible to preference.
As for the setup of [Manual TVG], see “To adjust with manual TVG”, p 2 - 60.
When shortenin g pulse length and narrowing frequency bandwidth are effective:
When the range used is less than 100 m and the response from dust and plankton on whole
screen is to be erased, it would be effective to set the pulse length at [Short] and the
frequency bandwidth at [Narrow].
By this setting, fine images such as dust and plankton are erased.
It can be used for highlighting of images of aimed fish and erasing of response smaller than those.
As for the setup of [Pulse Length], see “2.1.5 Selection of pulse length”, p 2 - 19.
As for the setup of [Frequency Bandwidth], see “2.1.6 Selection of frequency bandwidth”,
p 2 - 22.
When [Color Erase] is effective:
When the response from dust and plankton displayed in light bluish color is to be erased, it is
effective to use [Color Erase] function.
The response of dust and plankton displayed in stronger color than green could not be erased.
The color of aimed fish images and appearance of expanding response are displayed as it is
and unnecessary response from dust and plankton is erased.
<Example of images with color erasing>
Color erase 0 % Color erase 50 %