Measuring with limited instruments

At the present, instruments for measuring events inside a cell are limited. Although there are techniques using fluorophores to detect molecular events, they are not as quick and simple as GFP. 

So the question: is it possible to place GFPs at specific locations such that those different measurements will provide sufficient information for calculating some un-measurable point? 

Put in a different way: given a system, find a way to measure parameter X using a minimum number of other parameters (from a limited set of parameters).