honestly, this would give people a reason to use scanners....
set a base detection range based on ship size (assumption of multiple scanning arrays) with a max of 10km
That's well within lightning gun range.
Obviously when something shoots at you your scanners can see it now, but SUPRISE!
Adding scanners like, legendary grade (which I think go up to 400%) would increase your scanning range out to 50km.
I like the idea. Adds depth.