Spectral width of SuperDARN echoes: measurement, use and physical interpretation

Abstract

Abstract. The Doppler velocity and spectral width are two important parameters derived from coherent scatter radar systems. The Super Dual Auroral Radar Network (Super-DARN) is capable of monitoring most of the high latitude region where different boundaries of the magnetosphere map to the ionosphere. In the past, the spectral width, calculated from SuperDARN data, has been used to identify the ionosphere footprints of various magnetosphere boundaries. In this paper we examine the way the spectral width is presently estimated from the radar data and describe several recommendations for improving the algorithm. Using the improved algorithm, we show that typical spectral width values reported in the literature are most probably overestimated. The physical interpretation of the cause of various magnitudes of the spectral width is explored in terms of the diffusion and dynamics of ionospheric plasma irregularities.

A decade of the Super Dual Auroral Radar Network (SuperDARN): scientific achievements, new techniques and future directions

“…To date, the use of this technique has been under-exploited. However, this technique may be crucial to future understanding of the physics of ionospheric irregularities (as shown by its use by Ponomarenko and Waters 2006). A method has also been developed to examine SuperDARN measurements at an even more fundamental level.…”

“…For F-region backscatter it is usually the values determined from the Lorentzian fit that are used in further analysis (Hanuise et al 1993b). Recently, Ponomarenko and Waters (2006) have made a critical re-evaluation of the FitACF algorithm, revealing inadequate preprocessing of the experimental ACFs before using them to estimate the spectral width. They recommended a number of adjustments to the algorithm which affect the measured spectral width values.…”

Signatures of moving polar cap arcs in the F-region PolarDARN echoes

“…Regarding the broader RKN echoes as compared to the INV echoes it should be pointed out that the INV radar frequency was 10.6 MHz while the RKN radar frequency was 12.5 MHz. Ponomarenko and Waters (2006) established that echoes at lower radar frequency have typically smaller spectral width. In our case, the expected reduction factor of ∼1.2 allows the INV spectral widths to be similar in magnitude to the RKN spectral width.…”

The Behaviors of Ionospheric Scintillations Around Different Types of Nightside Auroral Boundaries Seen at the Chinese Yellow River Station, Svalbard

“…A computer controlled radar beams phase matrix sequence enables SuperDARN radar to estimate autocorrelation function (ACF) of each radar range gate, which is used to calculate SuperDARN radar 2-D Doppler or los velocity, scattered signal power. The spectral width is calculated from the decorrellation time of the ACF phase (Ponomarenko and Waters, 2005; and reference therein). SuperDARN observations provide the evidence of the auroral boundary movement and the ionospheric irregularity drift, which is directly related to the scintillation occurrences (Prikryl et al, 2015;van der Meeren et al, 2015).…”