Picosecond scale experimental verification of a globally convergent algorithm for a coefficient inverse problem

A globally convergent algorithm of the first and third authors for a 3D hyperbolic coefficient inverse problem is verified on experimental data measured in the picosecond scale regime. Quantifiable images of dielectric abnormalities are obtained. The total measurement timing of a 100 pico-seconds pulse for one detector location was 1.2 nano-second with 20 pico-seconds (0.02 nano-second) time step between two consequtive readings. Blind tests have consistently demonstrated an accurate imaging of refractive indexes of dielectric abnormalities. At the same time, it is shown that a modified gradient method is inapplicable to this kind of experimental data. This inverse algorithm is also applicable to other types of imaging modalities, e.g. acoustics. Potential applications are in airport security, imaging of land mines, imaging of defects in non-distractive testing, etc..