Direction finding
RDF was important in combating German threats during both the World War II Battle of Britain and the long running Battle of the Atlantic . 
<triplet> World War II <subj> Battle of Britain <obj> has part <subj> Battle of the Atlantic <obj> has part <triplet> Battle of Britain <subj> World War II <obj> part of <triplet> Battle of the Atlantic <subj> World War II <obj> part of