Recovering the total singularity of a conormal potential from backscattering data

The problem of recovering the singularities: of a potential from backscatte ring data is studied. Let Omega be a smooth precompact domain in R-n which is convex (or normally accessible). Suppose V-i = upsilon + w(i) with upsil on is an element of C-c(infinity) (R-n) and w(i) conormal to the boundary o f Omega and supported inside <(Omega)over bar> then if the backscattering d ata of Ii and Ii are equal up tc, smoothing, we show that w(1) - w(2) is sm ooth.