1974 PPDB (Point Positioning Data Base)
The 1974 PPDB (Point Positioning Database) vertical, black and white (panchromatic) aerial project was acquired by the U.S. Air Force (USAF).
The 1974 PPDB (Point Positioning Database) vertical, black and white (panchromatic) aerial project was acquired by the U.S. Air Force (USAF).