▁efforts ▁at ▁this ▁point ▁were ▁about ▁two ▁years ▁behind ▁the ▁British . ▁Un like ▁in ▁Britain , ▁where ▁the ▁major ▁targets ▁lay ▁only ▁a ▁few ▁minutes ' ▁flight ▁time ▁from ▁the ▁coast , ▁Germany ▁was ▁protected ▁by ▁large ▁tract s ▁of ▁neutral ▁territory ▁that ▁gave ▁them ▁long ▁times ▁to ▁deal ▁with ▁intr ud ing ▁bom bers . ▁Instead ▁of ▁air bor ne ▁rad ar , ▁they ▁re lied ▁on ▁ground - based ▁systems ; ▁the ▁targets ▁would ▁first ▁be ▁picked ▁up ▁by ▁rad ar ▁assigned ▁to ▁a ▁" cell ", ▁the ▁rad ar ▁would ▁then ▁direct ▁a ▁search light ▁to ▁" p aint " ▁the ▁target , ▁allowing ▁the ▁f igh ters ▁to ▁attack ▁them ▁without ▁on - board ▁a ids . ▁The ▁search light s ▁were ▁later ▁supp l anted ▁with ▁short - range ▁rad ars ▁that ▁track ed ▁both ▁the ▁f igh ters ▁and ▁bom bers , ▁allowing ▁ground ▁operators ▁to ▁direct ▁the ▁f igh ters ▁to ▁their ▁targets . ▁By ▁July ▁ 1 9 4 0 , ▁this ▁system ▁was ▁well ▁developed ▁as ▁the ▁K amm h uber ▁Line , ▁and ▁proved ▁able ▁to ▁deal ▁with ▁the ▁small ▁ra ids ▁by ▁isolated ▁bom bers ▁the ▁R AF ▁was ▁carrying ▁out ▁at ▁the ▁time . ▁ ▁At ▁the ▁ur ging ▁of ▁R . V . ▁Jones , ▁the ▁R AF ▁changed ▁their ▁ra id ▁tact ics ▁to ▁gather ▁all ▁of ▁their ▁bom bers ▁into ▁a ▁single ▁" stream ". ▁This ▁meant ▁that ▁the ▁ground - based ▁portion ▁of ▁the ▁system ▁was