Sonar echo reflection is greatly affected by sloping contour...
-A bottom contour sloping up (and out to the side) will make the image brighter because the echos can reflect better against the "upslope"...
-A bottom contour sloping down (and out to the side) will make the image darker because the echos cannot reflect as well from the "downslope"...
Harder bottoms will also reflect echos better than softer bottoms..Also making the image brighter....
There may be some advantage to scanning deep to shallow because the "upslope" (out to the side) is already reflecting better echos...needing a lower "SI Sensitivity" setting...
But there also may be some advantage scanning shallow to deep ... Needing a higher "SI Sensitivity" setting that could possibly make structure (such as brush) stand out better...
I find that different water conditions/bottom compositions require completely different SI Sensitivity settings...
Basically...
If my SI image starts getting dark- I increase SI Sensitivity..
If my SI image starts getting light- I decrease SI Sensitivity...
The "SI Sensitivity" setting is the most used setting on my 1197...
Rickie


Likes:
Thanks:
HaHa: 
Reply With Quote
Reaper, Where Fish come to Fry















