Tsing Hua Univ, Dept Phys, Beijing 100084, Peoples R China
; Univ Alabama, Dept Phys, Huntsville, AL 35899 USA
; Natl Space Sci & Technol Ctr, Huntsville, AL 35805 USA
; Chinese Acad Sci, Inst High Energy Phys, Beijing 100039, Peoples R China
We have developed a timing analysis method to determine the distances of variable Galactic X-ray sources based on the method advanced by Trumper and Schonfelder in 1973. The light curve of the halo produced by the scattering of X-rays off the interstellar dust is delayed and smeared. The differences between the power density spectra of the point source and the halo contains the information of X-ray source distance and dust distribution along the line of sight. We present the details of this method and demonstrate its validity for the future X-ray astronomy instruments by simulations.