Photometric catalog of nearby globular clusters I. A large homogeneous (V,I) color-magnitude diagram data-base

We present the first part of the first large and homogeneous CCD color-magn itude diagram (CMD) data base, comprising 52 nearby Galactic globular clust ers (GGC) imaged in the V and I bands using only two telescopes (one for ea ch hemisphere). The observed clusters represent 75% of the known Galactic g lobulars with (m - M)(V) less than or equal to 16.15 mag, cover most of the globular cluster metallicity range (-2.2 less than or equal to [Fe/H] less than or equal to -0.4), and span Galactocentric distances from similar to 1.2 to similar to 18.5 kpc. In this paper, the CMDs for the 39 GGCs observed in the southern hemisphere are presented. The remaining 13 northern hemisphere clusters of the catalo g are presented in a companion paper. For four clusters (NGC 4833, NGC 5986 , NGC 6543, and NGC 6638) we present for the first time a CMD from CCD data . The typical CMD span from the 22(nd) V magnitude to the tip of the red gi ant branch. Based on a large number of standard stars, the absolute photome tric calibration is reliable to the similar to 0.02 mag level in both filte rs. This catalog, because of its homogeneity, is expected to represent a useful data base for the measurement of the main absolute and relative parameters characterizing the CMD of GGCs.