Green's function retrieval and passive imaging from correlations of wideband thermal radiations
Matthieu Davy, Mathias Fink, and Julien de Rosny
Accepted
We present an experimental demonstration of electromagnetic Green's function retrieval from thermal radiations in anechoic and reverberant cavities. The Green's function between two antennas is estimated by cross-correlating milliseconds of decimeter noise. We show that the temperature dependence of the cross-correlation amplitude is well predicted by the black body theory in the Rayleigh-Jeans limit. The effect of a non-uniform temperature distribution on the cross-correlation time symmetry is also explored. Finally we open a new way to image scatterers using ambient thermal radiations.