Here, $j_U$, $j_D$ are the canonical elementary embeddings induced by the measures $U,D$ on $\kappa$.
I actually wish to ask three related questions.
Let Ult$_U(V)$, Ult$_D(V)$ be the transitive collapses of the ultrapowers of the universe $V$ mod $U,D$ respectively.
1) If $j_U = j_D$, is $U=D$?
2) If Ult$_U(V)$ = Ult$_D(V)$, is $U = D$?
3) If $j_U(U) = j_D(D)$, is $U=D$?
As you can see, these all revolve about the soft question, "To what extent can we reconstruct a measure given information about the elementary embedding it induces?"