Meteoric dust effects on D-region incoherent scatter radar spectra

We extend the incoherent backscatter radar equation for the weakly ionized, collision-dominated case to include polydisperse charged dust, using the fluid-equation approach. Calculations with this equation show that the main effect of charged dust on the radar Doppler spectrum is to narrow it, except in the case of very small, negatively charged dust, which widens the spectrum. The results are encouraging for the use of incoherent scatter radar as an instrument for meteoric dust measurement. We also note that if the effects of meteoric dust are not taken into account, one may get a systematic bias in the D-region parameters deduced from the radar spectra. This may account for the discrepancy between observed and calculated spectra reported in earlier papers. (C) 1998 Elsevier Science Ltd. All rights reserved.