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391001-N-NO204-0001.JPG Photo By: U.S. Naval Research Laboratory

washington - Naval Radar Systems: Radar Plan Position Indicator (PPI)-To provide a polar-coordinate map-like display of targets,NRL originated the radar plan-position indicator (PPI)-the well known radar scope with the round face and the sweeping hand-between 1939 and 1940. The PPI is now universally used by military and commercial interests around the world for the display of radar information for such functions as air and surface detection,navigation, air traffic control , air intercept, and object identification. Highlights of NRL's First 75 Years/RELEASED


This photograph is considered public domain and has been cleared for release. If you would like to republish please give the photographer appropriate credit.

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