Estimation of optimal parameter values for underground cylindrical objects and soil using Ground Penetrating Radar. [Doctoral dissertation] | Estimacija optimalnih vrednosti parametara podzemnih cilindricnih objekata i zemljista koriscenjem Georadara. Doktorska disertacija
2009
Ristic, A.
This thesis presents a new method to simultaneously estimate cylindrical object radius (R) and electromagnetic (EM) wave propagation velocity (v) from Ground Penetrating Radar (GPR) data. Since existing methods are based on a priori known v, the proposed method has an advantage: it eliminates the measurement of v and its influence on R estimation quality. Estimating v accurately results in better soil characterisation. Three steps are used to simulataneously estimate v and R. First, using the extracted raw data, the coordinates of the hyperbola apex (x0, t0) are estimated. Second, the boundary speed (v0) is estimated, based on the previous results. In the final step, v is reduced from v0 to a predefined vmin. From the analysis of propagation velocity choice criterion, an optimal v is chosen, which is used to calculate a unique R. This proposed method is a nonlinear least squares fitting procedure. The method is implemented and verified, using data collected under real conditions, in a Matlab environment. A comparison of the proposed and existing methods shows that the new method is significantly more accurate and robust with regard to noise and the amount of raw data.
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