We present a characterization of supercompactness measures for ω1 in L(R), and of countable products of such measures, using inner models. We give two applications of this characterization, the first obtaining the consistency of δ1 3 = ω2 with ZFC+ADL(R) , and the second proving the uniqueness of the supercompactness measure over Pω1 (λ) in L(R) for λ > δ2