Karl Rawer Karl M.A. Rawer (*19.4.1913) is the specialiste of radio wave propagation and the ionosphere who developed the shortwave prediction code used during WWII by the German forces and later by the French Navy. 1939, Rawer obtained his ph.d. under Jonathan Zenneck with a paper about partial reflection of electromagnetic waves in an ionospheric layer. He became employee of the Luftwaffe (Wehrmacht) and was 1940 charged by Johannes Plendl and Walter Dieminger to support communication officers at the difficult choice of suitable frequencies. Rawer developed an analytical code for calculating short wave transmission for given time and distance taking account of multiple paths between Earth and the variable ionosphere, of variable solar activity etc. Individual predictions for special conditions were also produced. From 1943 on predictions were used by Navy and Army too. After the war Yves Rocard, then director of research of the French Navy, engaged Rawer as directeur scientifique (1946-1956) of the Navy´s newly created "Service de prevision Ionospherique".