I say again, what use is the radar for detection of LW raids if british intelligence knew everything that LW knew before the raids were launched - targets, times, etc?
Ultra (codename for Enigma intercepts) was very rarely that good.
Coventry is often cited as an example, with the allegation Ultra revealed exact details of the plan, and Coventry was sacrificed to preserve the Ultra secret.
In fact, Coventry was identified along with two other cities in the Midlands, and 4 locations in the South East. All were given code names, and all identified as targets several days in advance.
The consensus of opinion on the day of the raid, however, is that London was to be the target. Coventry wasn't identified as the target until radar identified the bombers course.
If you take the BoB as an example, Ultra provided only one really valuable bit of information. In late September a message was intercepted ordering the dismantling of certain loading gear at German airfields, which meant the Germans were no longer intending to use paratroops in a major operation soon, which obviously meant the invasion was off.
However, no accurate targeting information was provided by Ultra, not even the German change in tactics to attack London.