seisDD Double-difference adjoint seismic tomography Yanhua O. Yuan; Frederik J. Simons; Jeroen Tromp Geophys. J. Int. 2016 : ggw233v1-ggw233. http://dx.doi.org/10.1093/gji/ggw233 READ INSTRUCTIONS