Contour plot of the electron number density for Condition 1, at 80 km altitude. The overdense region is highlighted. We have assumed a wavelength Λ = 6 m, which corresponds to a radio frequency equal to 50 MHz. For this condition, the region extends up to 100 m in the axial direction and 5 cm in the radial direction. Axes are not to scale and the freestream flows from left to right.