Modern ASW starts by assembling a picture before sending a platform to prosecute a contact. Open publications can reveal inventories and movements: Brassey's Naval Annual is used to show that even a wartime public volume could list smaller navies' ships, armaments, and other useful details. Satellites, patrol aircraft, friendly submarines, and intelligence services provide other pieces. Analysts must also judge whether a navy understates or exaggerates its capabilities, because the purpose is to build a realistic target profile rather than repeat published claims.
Chapter · 45:57-59:24
Modern ASW begins with an information picture
Satellites, patrol aircraft, friendly submarines, espionage, and open sources all contribute clues needed to find and classify submarines.