CALIFA, the Calar Alto Legacy Integral Field Area survey I. Survey presentation

S.F. Sanchez, R.C. Kennicutt, A.G. de Paz, G. van de Ven, J.M. Vilchez, L. Wisotzki, D. Mast, J.A.L. Aguerri, S. Albiol-Pérez, Anna Rita Gallazzi, Stefano Zibetti