HARRY L. VAN TREES, ScD, was Professor of Electrical Engineering at Massachusetts Institute of Technology. He served as Chief Scientist of the U.S. Air Force, Chief Scientist of the Defense Communications Agency, and Principle Deputy Assistant Secretary of Defense for C3I. He was President of M/A-Com-Linkabit Government Systems and a cofounder of CommQuest Technologies. He is currently Distinguished Professor of Electrical Engineering and Director of the C3I Center of Excellence at George Mason University, Fairfax, Virginia.