Looking for Advice on R10 Layout / Setup

We have a 10' x 20' carport that I've turned into my temporary simulator while I figure out how and where to fit it in the house.  Out of the box, both here and at the range, it reads very short (20-30 yards) for most irons, and is worse with woods.  I know it's radar-based.  Is there any material that could help clean up the readings?