Imaging F Region Drifts Using Monostatic Phased-Array Incoherent Scatter Radar

Abstract

We develop a technique for using monostatic, electronically steerable incoherent scatter radar (ISR) to generate 2-D estimates of F region flow fields. Tikhonov regularization is used to achieve robustness in the presence of spatial variation. The regularization functional imposes partial incompressibility on the medium and is therefore physically justified. Although the estimator has difficulty resolving sharp discontinuities, it performs well in regions of uniform flow. In order to characterize the effect of the regularization parameter, we test the performance of the operator in three simulated scenarios. We then analyze data from an experiment on the Poker Flat ISR. The experimental results are validated against coregistered all-sky optical data and are found to be mostly consistent with these independent measurements. Namely, the radar-derived estimates show a reduction of ion flow wherever the optical data indicates an auroral enhancement. The estimated flow is directed parallel to an arc boundary, consistent with an electric field directed toward the arc.