Thread: humminbird greg

These guys explained that very well..

I would offer to add... Always consider that sonar is not a "camera" looking down into the water..It's a sound wave transmitter..

Everytime the unit "pings" ...a sound wave (in the shape of the specific beam angle) is sent thru the water...

Echos received in that "ping" are processed and "plotted" onto the unit's screen in a thin strip (a few pixels wide) to the far right of the 2d or DI screen...

The very next "ping"s echo data is processed and plotted onto the far right of the screen....pushing the previous "ping" data to the left...

This "stacking" of echo data into strips onto the far right of the unit screen ...is what "builds" the screen image on the unit screen...

The only data showing on the screen image that is currently under the xducer.. Is the strip at the far right of the screen... Everything to the left of that thin strip on the screen is "history" that the xducer has already passed over...(and no longer in the sonar beam)...

Rickie