ILS works pretty much the same way as the Lorenz/Knickebein system used in WWII by the Germans to guide bombers (described in https://news.ycombinator.com/item?

ILS works pretty much the same way as the Lorenz/Knickebein system used in WWII by the Germans to guide bombers (described in https://news.ycombinator.com/item?id=19737056 https://news.ycombinator.com/item?id=19737056), so the attack described in TFA sounds basically the same as the countermeasures deployed by the British.