Let’s start by acknowledging that calculating distance to any target in the SI image is not simply
“subtract water depth from the SI range to get distance to target”...
It is physically and scientifically impossible for any Sonar beam (sound traveling in water) to travel to point A and then change directions to get to point B (as in the common misconception of measuring from the xducer to the lake bottom and then measuring out from that point) ...
Horizontal Distance to any target in the SI image is a
”slant range CALCULATION using the Pythagorean Theory” ...
Using the OP scenario of 10’ water depth and seeing a target in the SI image 25’ away from the SI image center line ...:
Attachment 362855
Next we will delve into the HB software engineer’s minds to explain why the HB software engineers designed the SI image layout as they did ...
But 1st I will give space for questions ...
Rickie