 Complete the following phrase:  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 