 Nyorai kupfuurira kweiyi ndima - Pashure peHondo yepamhepo ya1939 yeHeligoland Bight, kudenha mabhomba kweRoyal Air Force RAF kwakachinjirwa kuvhariro yerima, kutanga mushandirapamwe weDziviriro yeReich. Pakazosvika pakati pa1940, Generalmajor Brigadier General Josef Kammhuber akanga asimbisa gadziriro yokuzvidzivirira pamhepo usiku inonzi Kammhuber Line. Yakanga iine nhevedzano yezvikamu zvekutonga zvakagadzirirwa radars uye searchlights uye murwi wehusiku akabatanidzwa. Chikamu chimwe nechimwe, chinonzi Himmelbett mubhedha wedenga, chaizotungamirira murwi wehusiku kupinda munharaunda inooneka nevanopfura mabhomba. Muna 1941, Luftwaffe yakatanga kugovera ndege dzokurwisa usiku nemaradar airborne akadai seradar Lichtenstein. Iyi radar inotakurwa nendege haina kupinda mukushandiswa kwavose kutozosvikira pakuvamba kwa1942. 