Arcturus (Achtung Achtung Bomber Command)

Gents, I’m just decoding a Friends Grandad’s Navigators log for a Stirling sortie to Hamburg on 29th July 1943. It’s full of interesting Bomber speak with references to Mandril and Boozer but I’m stumped with ARCTURUS as they reach the English coast on the way home at 03:20.

The previous entry is ‘Astro’ and a quick google search reveals that ‘Arcturus’ is the brightest visible star which would be appropriate for an Astro navigational fix but I’m wondering if there is more to it……….

Does anyone know the code name given to the vertically positioned searchlights dotted around the Country to aid navigation? Being the brightest star, Arcturus would also be an obvious choice of name but I can’t seem to find any gen on the subject.

Would be great to shed some light on it:)