Rowehl Geschwader Top-secret Luftwaffe squadron that conducted high altitude photo-reconnaissance flights deep into Russia to gather military intelligence for Operation Barbarossa. It was set up by Lieutenant Colonel Rowehl in October 1940 by direct order of Hitler and was the forerunner of the U.S. U-2 flights of the 1960's. One group flew from Insterberg over the Baltic States using special Do 215's equipped with high-altitude engines. A second unit flew out of East Prussia and used HE111s while a third flew between Minsk and Kiev in Ju 88's and Ju 86's. All flew at between 33,000 and 39,000ft, enabling thern to photograph every Red Air Force base. http://www.ww2guide.com/germanb.shtml
The Ju-188 pictured on that site was excellent. I have never seen that picture before. It must have given the allied pilots a pause to try and figure out what the thing is.
Just read a teasingly short paragraph on this in Operation Barbarossa which debunks the idea of Axis ignorance of Soviet build up and preparations. Since the above link is dead, I have gone looking for further leads on this interesting subject. http://www.warhistoryfans.com/secret-german-squadron-in-ww2-kg200-185272.html Luftwaffe's Secret KG 200 in World War II http://www.militaryhistoryonline.com/wwii/articles/airrecon.aspx