Before revision: MEFs are determined by taking the point of highest elevation within a quadrangle, adding 100 feet for vertical error , then adding the height of the highest obstacle in the quadrangle or 200 feet, whichever is higher, then rounding up to the next hundred feet.
After revision: MEFs are determined by taking the point of highest terrain within a quadrangle, adding 100 feet for vertical error ; or2) The height of the highest obstacle in the quadrangle , adding 100 feet for vertical errorandhighest of the following: 1) The200 ft for obstacles which are not required to be portrayed, and then addingmanmade then rounding up to the next hundred feet.