جستجوی مقالات مرتبط با کلیدواژه « وارون سازی سه بعدی » در نشریات گروه « فنی و مهندسی »

Investigating the possibility of underground structures detection is one of the complicated problems. In this paper, magnetic data have been used and both direct and inverse problems have been considered. In direct problem, with the assumption of the known size and position of the structure, magnetic response is modeled. Then, using the modeled signals, some points about the detectability of the structures are discussed. In inverse problem, position of the underground target is estimated based on the analytic signal and Euler deconvolution methods and 3D inversion of the magnetic data. Finally, both of the direct and inverse problems are implemented based on the simulated data and some suggestions are made to decrease the probability of detectability of the underground targets. The results show a concealed military structure with a susceptibility more than 0.05 SI and the depth of less than 200 m can be detected and located in a nonmagnetic host rocks using aeromagnetic survey with a resolution more than 60 m between lines. With increasing the magnetic susceptibility of structure, the possibility of detection will be increased; so that if the susceptibility exceeds 0.01 SI, the possibility of detection will be increased to depth of 400 m.

The goal of this study is to process and interpret gravity data acquired from Sabzevar chromite exploration area by using geophysical filters such as trend removal, tilt angle, hyperbolic tilt angle. it is also aimed to compare the result of mentioned filters with one of the most effectivemethods in 3-D inverse modeling of geophysical data, named Li-Oldenburg algorithm. The inversion procedure resembles optimization process and the purpose is to find a model that minimizes the model objective function and produces model’s data that could be validated by the original observations. For comparing each filter with the result of 3D modeling, it is tried to choose the best view of final model. The comparison’s results indicate that the outcome of 3D inverse modeling is in good agreement with those of applied filters. The research’s outcome represents that there are two faults with surface outcrops in the south and center of the area, and also a variable lithology with north-south direction in the west.There can also be seen several outspread deposits of chromite with bottom’s depth of 25 meters, and a main anomaly at the west of the area which laterally extend up to 45 meters depth.