The paper discusses the process of forming satellite data samples, considering various selection strategies. These strategies include sampling measurements near grid nodes (different grids used), selection of data obtained at a certain altitude above the Martian surface, and selection of data obtained in the absence of direct visibility of the Sun (nighttime data). The use of such criteria allows to create an optimal data sample necessary for constructing an accurate and reliable model of the Martian crust magnetic field using the S-approximation method.