Koden CVS-702D, Basic Operation Manual

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Chapter 2 Basic operation CVS-702D
2-68 0093107022-02
2.3 Changing of the image scroll speed
The image scroll speed can be changed at 13 steps of [Speed -2], [Speed -1], • • • [Stop],
[Speed 2], • • • [Speed 9]. The larger the speed number is, the slower the image scroll speed
becomes.
The image scroll speed of echo sounders is faster for shallow ranges and slower for deeper
ranges depending on the display ranges.
When the image speed at shallow ranges seems too fast, [Image Speed] is used to make the
speed slower.
When sea bottom is bedrock and has strong reflection strength, the multipath reflection
between seawater surfaces remains as reverb and
may display false image*
1
. To eliminate
the false images , the image scroll speed may be slowed down to wait the next transmission
and reception until the reverb disappears.
The scroll of images can be stopped.
Speed 0 : The image scroll speed is 2 times faster by enlarging the original image 2 times.
Speed -2: The image scroll speed is 4 times faster by enlarging the original image 4 times.
To change image scroll speed:
1. Press [Image Speed] key .
[Image Speed] adjustment box is displayed.
To speed up image scroll speed:
1. While [Image Speed] adjustment box is displayed, press [Image Speed] key .
Move upward the cursor, and [Image Speed] is set to a faster speed.
*
1
False image: When sea bottom material is bedrock with high reflection ratio of ultrasonic sound, the reflected signals at
the sea bottom are reflected by the seawater surface and again by the sea bottom. This may be repeated
many times. This repeat of reflection remains as reverb. If the reverb remains at the next transmission and
reception, the image is a mixture with normal reflection and the reverb. This reverb is called as false
images.
Speed -2 4 times faster
Speed -1 3 times faster
Speed 0 2 times faster
Speed 1 1.5 times faster
Speed 2 Normal speed
Speed 3
Speed 4
Speed 5
Speed 6
Speed 7
Speed 8
Speed 9
The image speed
becomes slow in order.