  Frequency-angular distributions for THz emission in the range of 0.1 - 3 THz
generated in a single-color laser filament plasma situated both under and
without electrostatic field are for the first time experimentally studied. The
angular distribution for various spectral components of this THz emission is
demonstrated to differ significantly. The maximal propagation angles for these
components grow up under the electric field, the angular distribution for the
low-frequency THz emission depending significantly on the laser pulse energy in
contrast to the case of no electric field. An increase in the laser pulse
energy leads to a decrease of the propagation angles for low-frequency THz
emission and to disappearance of the local minimum in the angular distribution
on the propagation axis.
