  We present a unified elucidation for the role temporal coherence properties
of x-rays in surface x-ray standing wave analysis, under total external
reflection condition. Analytical formulas have been derived that provide a
direct relation between the intensity distribution of x-ray standing wave (XSW)
pattern and complex degree of coherence of the incoming x-rays. The novelty of
the proposed method has been demonstrated experimentally together with the
theoretical results for a real application by analyzing the distribution of
metal nanoparticles on a Si mirror surface. Our results demonstrate that the
modified XSW approach opens up an opportunity to unambiguously interpret
structural studies of large dimension nanostructure materials of height 200nm
(or more), deposited on a substrate surface.
