Ben Dewell wrote a document on October 31, 2015 about understanding heights and vertical datums that is estimated to take between .75 to 1 hour to complete. The document discusses different methods of measuring heights and elevations as well as vertical reference systems used as a basis for measuring elevation.

1. Ben Dewell
Understanding Heights and Vertical Datums
Time to complete: .75 - 1.00 h
October 31, 2015