Ivan A. Getting, a physicist and electrical engineer who envisioned and then pushed for the development of today's ubiquitous Global Positioning System, has died. He was 91.

GPS is considered the most important achievement in navigation in the 20th century.

During World War II, Getting directed the Division of Fire Control and Army Radar at the MIT "Rad Lab"; his group developed the microwave tracking radar that was credited with destroying 95% of the V-1 cruise bombs used by Germany against England.