"Is the red dot where they pinpoint?"
They are the markers that Tesoro put on themselves. On the concentric, it's centered as typical. On the wide scan (DD), its at the toe which is typical, but I lots of times will swing it side to side, turn and do it from another angle or two, and visualize the peak response on the ground surface, like X-ing. Or pull it till the signal drops - works either way for me.