Japanese strenghtening of defence of Rabaul area according to the U.S. Joint Intelligence Committee. Daily summary dated 20 April 1942

An item reported the continue strenghtening by the Japanese of the Rabaul area [Papua New Guinea] especially with aircraft although even with some submarinies.

Source

Map Room Papers (Roosevelt Administration), 1942 - 1945. U.S. Joint Intelligence Committee. Daily summary No. 131 dated 20 April 1942