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Modern Geomatics Technologies and Applications

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techniques predicated on satellite image processing (e.g. InSAR ).
Geotechnical methods are derived from installation some mechanical tools

(such as strain meters and so on) inside deformable body. In this paper, the
results obtained from geodetic observations have been compared with the

outcomes of dam instrumentation. Also, based on the numerical analysis

(FEM), the future behavior of the dam was evaluated.

2.1. Geodetic methods

One of the most common and reliable methods for studying the structures is
development of precise geodetic networks around and on its body and then,

performance of periodic measurements for determination of displacements.

Traditional geodetic surveying methods provide useful information about the
status of the overall movement of the mark points, along with transmission

and rotation of body, through the connection involving the measurement

stations. Conventional surveying methods such as triangulation, traversing
and geometric leveling have already been utilized in monitoring systems and

many large engineering structures such as dams, bridges and high-rise
buildings have been controlled using these methods. In these approaches, sub-

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millimeter accuracies in small areas and the relative accuracy of 10 are
achievable.

Conventional and satellite surveying methods need direct visibility between

surveying stations or between ground stations and the satellites and therefore
these methods (as well as short-range photogrammetry methods) are only

1 Interferometry Synthetic Aperture Radar