concluded that:
we need 2 flat surfaces (50 x 50 mm) on each half tank with a laser tracker target holder socket (hole with diameter 10 mm and depth of 11-12 mm),
these sockets will be on 2 small cylinders, which are welded onto the left side of the structure (looking downstream). Ideally there should be an angle of 90 degrees between and be located at 45 and 135 degrees. Since there must be a direct line of sight from the side of the structure for laser tracker we have to make sure that the support is not in the way and it is likely that we have compromise on the idea conditions for the targets.