We have developed a theory of auroral radar spectra for conditions under which Farley-Buneman waves should be strongly excited in the high-latitude E region. The theory assumes that the unstable waves spend the larger part of their lifetime in a linear growth phase. It also uses a previously unexplored property of the waves, namely, that waves with different wave vector components along the magnetic field have markedly different phase velocities. We have constructed synthetic auroral radar spectra for 1-m size irregularities. We have calculated the width of the spectra, their mean Doppler shift, and anisotropy. We have studied how the properties of spectra produced by Farley-Buneman waves are affected by the presence of ion drifts and neutral winds, by the electron temperatures and densities, by the neutral atmospheric profile, and by the strength of the dc electric fields. The results seem to be in good qualitative agreement with existing observations. |