  An inverse obstacle scattering problem for the electromagnetic wave governed
by the Maxwell system over a finite time interval is considered. It is assumed
that the wave satisfies the Leontovich boundary condition on the surface of an
unknown obstacle. The condition is described by using an unknown positive
function on the surface of the obstacle which is called the surface admittance.
The wave is generated at the initial time by a volumetric current source
supported on a very small ball placed outside the obstacle and only the
electric component of the wave is observed on the same ball over a finite time
interval. It is shown that from the observed data one can extract information
about the value of the surface admittance and the curvatures at the points on
the surface nearest to the center of the ball. This shows that a single shot
contains a meaningful information about the quantitative state of the surface
of the obstacle.
