Survey/Alignment check by looking into the double residual distribution of pixel hits in ladder overlapping regions.
 See attached compressed file for total 166 plots. (for lack of statistics,sector 3,8 are not shown)

• Both local and global double residual of inner/outer layers are checked 
• Corrections are done to the local residual by considering the effect from ladder relative angle. (applied survey geometry) 
• dX/dY are seen generally within 10 micron
• Average hit resolution 15.8/1.414 ~ 11.17 micrion (ladders in good statistics)