Irregularity Parameter Estimation for Interpretation of Scintillation Doppler and Intensity Spectra

Abstract

We investigate the Irregularity Parameter Estimation (IPE) technique for characterizing ionospheric irregularities using satellite beacon observations of amplitude and phase scintillation. The approach is to fit either the Doppler spectrum or the intensity spectrum of scintillation observations with theoretical fitting functions derived for the case of propagation through a thin phase changing screen. Fitting the Doppler spectrum yields estimates for the phase spectral strength, spectral index, and effective scan velocity. Fitting the intensity spectrum provides estimates for these parameters, and additionally the Fresnel scale. We find that fitting the intensity spectrum tends to provide more robust and accurate results than fitting the Doppler spectrum. Nevertheless, fitting the Doppler spectrum is simpler and generally produces acceptable estimates of phase spectral strength and spectral index.