Sejong Open cluster Survey (SOS). 0. target selection and data analysis

Star clusters are superb astrophysical laboratories containing cospatial and coeval samples of stars with similar chemical composition. We initiate the Sejong Open cluster Survey (SOS) - a project edicated to providing homogeneous photometry of a large number of open clusters in the SAAO ohnson-Cousins' UBV I system. To achieve our main goal, we pay much attention to the observation of standard stars in order to reproduce the SAAO standard system. Many of our targets are relatively small sparse clusters that escaped previous observations. As clusters are considered building blocks of the Galactic disk, their physical properties such as the initial mass fuunction, the pattern of mass segregation, etc. give valuable information on the formation and evolution of the Galactic disk. The spatial distribution of young open clusters will be used to revise the local spiral arm structure of the Galaxy. In addition, the homogeneous data can also be used to test stellar evolutionary theory especially concerning rare massive stars. In this paper we present the target selection criteria, the observational strategy for accurate photometry, and the adopted calibrations for ata analysis such as color-color relations, zero-age main sequence relations, Sp - M_V relations, Sp - T_eff selations, Sp - color relations, and T_eff - BC relations. Finally we provide some data analysis such as he determination of the reddening law, the membership selection criteria, and distance determination.