The bump before the bump

I am asking for a clarification on the arena. I cannot access the field drawings at my home because of some sort of computer problem, but could not find the answer I wanted via the drawings at school.
My question is: There is a some sort of protective baseplate that lies under the bump. This causes an higher spot in the carpet near the bumps. I am wondering how much higher the carpet is, and how far from the bumps this protective plate ends.

Thanks in advance.

It can vary, but figure about 1/2 inch or so.

There is a better description in Team Update #2