The amplitudes of one-dimensional periodic profiles were analyzed as functions of annealing temperatures to determine surface diffusion constants and activation energies with high lateral resolution. The temperature dependence of the surface self-diffusion constant was derived for temperatures between 573 and 1073 K by Fourier analysis of the profiles. A temperature-dependent study of the surface of nanocrystalline Au revealed an increase in grain size with rising temperature and the ratio of free energy on the surface and at grain boundaries.