Inversion algorithms and measurement systems for microwave tomography of buried objects
Résumé
The detection and identification of buried inhomogeneities using electromagnetic waves are of crucial importance for many nondestructive testing applications. The paper deals with two different inversion algorithms for microwave tomography. First, a qualitative algorithm based on diffraction tomography for detecting the buried object, and second, a quantitative algorithm for reconstructing the complex permittivity profile of the object. The backscattered field is measured at different frequencies over a probing line above or in contact with the soil at different receiver locations and for difference positions of a transmitting antenna (multistatic configuration). The two reconstruction algorithms process the backscattered field generated by the buried inhomogeneities and incorporate the incident near-field radiation pattern transmitted in the soil by the broadband antenna. Tomographic reconstructions of buried objects are presented for a situation of practical interest using bow-tie antennas in the frequency band 0.3-1.3 GHz.
Mots clés
method of moments
inverse problems
conjugate gradient methods
computerised tomography
image reconstruction
microwave imaging
antenna radiation patterns
permittivity measurement
microwave tomography
buried objects
inversion algorithms
measurement systems
buried inhomogeneities
qualitative algorithm
diffraction tomography
quantitative algorithm
complex permittivity profile reconstruction
backscattered field
multistatic configuration
incident near-field radiation pattern
broadband antenna
bow-tie antennas
inverse scattering problem
biconjugate gradient method
soil medium
lossy medium
moment method
0.3 to 1.3 GHz
Microwave measurements
Tomography
Buried object detection
Frequency
Soil
Broadband antennas
Electromagnetic measurements
Electromagnetic scattering
Nondestructive testing
Electromagnetic diffraction