Henri Calandra obtained his M.Sc. in mathematics in 1984 and a Ph.D. in mathematics in 1987 from the Universite des Pays de l’Adour in Pau, France. He joined Cray Research France in 1987 and worked on seismic applications. In 1989 he joined the applied mathematics department of the French Atomic Agency. In 1990 he started working for Total SA. After 12 years of work in high performance computing and as project leader for Pre-stack Depth Migration Research, he became head of Total USA’s Geophysics Research Group for 3 years in 2002 and coordinated Depth Imaging Research for the worldwide group until mid 2007 He is now technical advisor in depth imaging and high performance computing.