We used 1627 faint ( 15.5 \leq R \leq 23 ) stars in five fields of the Calar Alto Deep Imaging Survey ( CADIS ) to estimate the structure parameters of the Galaxy .
The results were derived by applying two complementary methods : first by fitting the density distribution function to the measured density of stars perpendicular to the Galactic plane , and second by modelling the observed colors and apparent magnitudes of the stars in the field , using Monte Carlo simulations .
The best-fitting model of the Galaxy is then determined by minimising the C-statistic , a modified \chi ^ { 2 } .
Our model includes a double exponential for the stellar disk with scaleheights h _ { 1 } and h _ { 2 } and a power law halo with exponent \alpha . 24 480 different parameter combinations have been simulated .
Both methods yield consistent results : the best fitting parameter combination is \alpha = 3.0 ( or \alpha = 2.5 , if we allow for a flattening of the halo with an axial ratio of ( c / a ) = 0.6 ) , h _ { 1 } = 300 pc , h _ { 2 } = 900 pc , and the contribution of thick disk stars to the disk stars in the solar neighbourhood is found to be between 4 and 10 % .