With the advent of large wide-field cameras and deep, CCD-based “all-sky” surveys, the study of the structure of the Milky Way (MW) through its stellar populations has become feasible. We are developing tools to apply CMD fitting techniques for this purpose. Here we present two applications. First we constrain the properties of the old and young stellar populations of the Canis Major overdensity. Secondly, we demonstrate how CMD fitting can be used to detect faint overdensities in the halo of the MW and determine their properties, using data from the Sloan Digital Sky Survey (SDSS).
