Lorenz FISH PRO HD+, Руководство пользователя

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37 User Manual
strong thermocline or surface clutter may be interpreted by the Fish Finder as
the bottom.
6.11 At a very shallow range upper half of the screen appears
almost completely filled by the surface clutter. How can
I eliminate it?
This is normal in shallow waters. To clean up the surface clutter without de-
grading the digital depth readout algorithm functionality there are two modes:
1) if Surface Declutter = OFF, it is possible to set the STC value to custom
setting the STC length to the same size of the surface clutter, and increasing
the STC strength until the image on the screen cleans up. Please note that in
very shallow waters it is usually better to switch to manual gain mode to
reduce gain fluctuation due to rapidly changing bottom conditions. 2) Using
Surface Declutter, increase the SD value until the surface declutter disap-
pears completely.
6.12 Why do I never see fishes in the range between 0 to 0.7
meters?
The minimum range of the Fish Finder is 0.7 meters. In this interval the Fish
Finder can detect neither the bottom nor any target.
6.13 How can I reduce the surface clutter?
You can act by: properly setting the STC as described at 6.11 and also by
increasing the NOISE LEVEL and reducing the GAIN or the GAIN OFFSET (if
you are in auto gain mode). However please note that a strong attenuation of
surface clutter may also reduce the capability to detect targets.
6.14 The Fish Finder is in auto gain mode but the picture
display too many small targets, what shall I do to
reduce the screen clutter?
Try increasing the NOISE LEVEL or decreasing the GAIN OFFSET.
6.15 In very shallow waters when the AUTO GAIN mode is
selected there are fluctuations in the bottom profile
width and its color representation. What should I do?
In very shallow waters the environment situation (bottom/water condition)
vary very quickly thus causing the auto gain algorithm to create oscillations
while trying to set optimal GAIN value for each situation. To avoid this it is
advisable to switch to MANUAL GAIN mode and fine tune the GAIN to a fixed
setting.
6.16 In very deep waters even setting the GAIN to its max-
imum value I cannot see the bottom what shall I do?
Try decreasing the NOISE LEVEL. If still the bottom is not visible there is
nothing you can do, the bottom echo is simply too weak to be detected.