Post-processing and visualization of ISR data

Incoherent scatter radar (ISR) techniques provide reliable measurements for the analysis of ionospheric plasma. Measurements of electron and ion densities, temperatures, and line-of-sight velocities are derived by employing antennas that transmit and receive radio waves. Recent developments in ISR technologies are capable of generating high-resolution volumetric data from multiple beam measurements. Examples of such technologies employ the so-called phased array antennas like the AMISR in North America or the upcoming EISCAT_3D in the northern Fennoscandia region. Traditional visualization methods, for example, 2D projections, applied to volumetric images render a reduced set of the available data and important aspects of the data may be lost to the analyst.
     
We present an interactive approach for the exploration and visualization of spatio-temporal and volumetric ionospheric data. The strategy is targeted at offering the analyst a wider range of alternatives in order to interpret ISR data. The proposed novel strategy allows for the reconstruction of ionospheric volume images by means of a novel sparse interpolation algorithm tailored for the particular features of ISR data. The interpolation offers estimation of gradients and processing of the challenging case of missing data. The reconstructed image is output by using volume rendering combined with customizable transfer functions. We propose to utilize reconstructed volumetric images for the estimation of ionospheric conductivities and volumetric currents, which in turn can be used for studying the evolution of storms and substorms in the ionosphere.