The Measurement Method Of Rock Dielecule Characteristics Based On Microwave Interference Technology

The dielectric characteristic of rock is an important characteristic characterizing its electromagnetic radiation characteristics,the dielectric constant as the core physical parameters of dielectric characteristics,characterized by the propagation,absorption,scattering and other characteristics of rock electromagnetic waves,it is the most basic physical parameters to describe the electromagnetic radiation of rocks.At present,there are many test methods for rock dielectric constants,but there are limitations such as complex operation,higher cost or only local point data,and in view of the above deficiencies,based on microwave interference theory,combined with rock microwave bright temperature observation experiments,a new rock dielectric constant test method is proposed,and numerical simulation and experimental verification of the method,the main results are as follows:(1)A method of inverting the dielectric constant of the test piece by changing the observation angle and changing the thickness of the test piece is proposed,and the accuracy of the method is verified by comparing it with the value of the dielectric constant inversion by other reliable methods.Based on microwave radiation transmission theory and microwave interference theory,the theoretical relationship between dielectric constant and observation angle change or thickness change is deduced,and the method of inverting dielectric constant at the test piece thickness unchanged changes the observation angle and the method of changing the vertical observation of the test thickness inverse dielectric constant are proposed,and numerical simulation is carried out based on this method,and the theoretical value of dielectric constant is obtained by the two methods.(2)To carry out microwave bright temperature observation experiments of Dali rock,granite and sandstone three kinds of rock at the same thickness,it is found that the microwave periodic volatility characteristics of sandstone are most obvious,in the range of 5 to 35 degrees,due to Under the influence of environment and other factors,the bright temperature of rock microwave radiation shows a monotonous downward trend with the increase of observation angle,and there is no obvious volatility.Using the method of inverting dielectric constant at the observation angle with the same thickness of the test piece changing the observation angle,the dielectric constant of the anti-performance sandstone was 2.28,and the result was close to the test result of the rock dielectric constant inversion method based on microwave radiometer 2.38,which proved that the method of changing the observation angle inversion dielectric constant by the thickness of the test piece was feasible.(3)To carry out the sandstone microwave bright temperature observation experiment at different thicknesses and vertical observation angles,the resulting thickness-bright temperature curve periodic fluctuation characteristics are unstable,which is due to the discreteness of the dielectric constant of sandstone plate test pieces.Considering that the experimental process should be convenient to change the thickness,and the selected test piece dielectric constant consistent requirements,this paper chooses to use tail sand to continue to change the thickness vertical observation inverse dielectric constant experiment,tail sand thickness-bright temperature curve periodic volatility characteristics are obvious and the fluctuation cycle is close,the thickness change corresponding to the fluctuation cycle is about 1.15 cm,the use of change test thickness vertical observation inverse dielectric constant method to reverse the dielectric constant results of about 16.Very close to the result of the rock dielectric constant inversion method based on microwave radiometer 16,so the method is considered feasible.