By the opening of the Battle in July the German "Luftwaffe" operational units were well aware of CH, and had been informed by the DVL that they could not expect to remain undetected, even in clouds. However, the "Luftwaffe" did little to address this and treated the entire topic with some level of disdain. Their own radars were superior to CH in many ways, yet in actions they had proven to be only marginally useful. During the Air Battle of the Heligoland Bight in 1939, a German Freya radar detected the raid while it was still an hour away from its target, yet had no way to report this to any of the fighter units that could intercept it. Getting the information from the radar to the pilots in a useful form appeared to be a difficult problem, and the Germans believed the British would have the same problems and thus radar would have little real effect.