Since the shape (as well as the integral) of the solar irradiance spectrum above the atmosphere is different than that below it, is the efficiency of photovoltaic solar panels defined and measured differently than those for terrestrial applications?
In the related question Why are these multi-junction solar cells 40% efficient on earth but 30% in space? some of the issues mentioned there are related to ratings - which are likely to be conservative lower limits. Here I'm asking about the definition of efficiency and its testing procedure and how it may differ when applied to panels destined for space and terrestrial applications.
above: Solar spectrum from here.