Default [Q] Google Maps, Sky and compass dont point in the right way

Hi,

I think something is wrong with the inner compass of my S4...
things like google maps google sky or a compass app aren't working properly. if I use maps navigation while walking the blue arrow points to a different direction than which i'm walking, If i'm pointing Google sky on say the great bear it is way of and if i open a compass app and point my phone to north it reads south west.

is this an hardware flaw? or something i can recalibrate?

thanks for your help!

Rudi