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We have developed a tomographic diffractive microscope in reflection, which permits observation of sample surfaces with an improved lateral resolution, compared to a conventional holographic microscope. From the same set of data, high-precision measurements can be performed on the shape of the reflective surface by reconstructing the phase of the diffracted field. Doing so allows for several advantages compared to classical holographic interferometric measurements: improvement in lateral resolution, easier phase unwrapping, reduction of the coherent noise, combined with the high-longitudinal precision provided by interferometric phase measurements. We demonstrate these capabilities by imaging various test samples.

Based on a large number of data including GPS monitoring of surface deformation and inclinometer monitoring of internal deformation over 7 years, we find that the displacement of a typical landslide mass has the stepped evolution characteristics as: the variation of the reservoir water level under the different years and months in the Three Gorges Reservoir and the deformation of landslide mass surges in the flood season. On the contrary, the deformation of landslide mass slows down in the non-flood season. Especially, in 2007, 2009 and 2011, the fluctuation of the surface monitoring displacement is more intense than that in the other years. In addition, the whole landslide mass has a characteristic of the trial-type sliding. The surface displacement is greater than the internal displacement. Based on that, deformation characteristics, stability mechanisms and the influencing factors of landslide mass are studied deeply. The results show that the drawdown of the water level of the Three Gorges Reservoir region is the main controlling factor of the deformation of the landslide mass. The results of the study have a significant value of reference on the stability analysis of landslide mass under the similar engineering geological conditions.