Topic: Autochart Live

[95Ranger]

Which sonar beam is used to generate maps using Autochart Live? Is it the 2D sonar or DI or SI? If the water depth is 25 ft, the 2D sonar would be surveying a 25 ft circle on the lake bottom, with no way of knowing exactly where the actual depth changes are occuring. For instance, a hump could be anywhere within a 25 ft circle. So how does it make accurate contour plots with 1 ft levels if it does not accurately know where the humps and valleys are relative to the boat position?

[Bob B]

Pretty sure it uses the 200khz beam .... which would be 1/3 depth ..... No idea how the algorithm works.  A steep depth change shows as wider bottom return on the unit.  Approaching from more than one angle would probably help improve the map.