Hi Nick,
I read the Luftwaffe reconnaissance part with much interest. By far too many legends have been published about Luftwaffe actions prior to and during D-Day. By now they are about to become facts.
Within my own sphere of research I was fortunate to get sources that enabled my to to tell the radar story. "The invasion fleet was not detected by radar on 6 june", wrong please see:
http://www.gyges.dk/pre_dday_attacks_on_the_german.htm
bregds
SES
www.gyges.dk