2011 SuperDARN Workshop       

A comparison of SuperDARN ACF fitting methods

A.J. Ribeiro (1), P.V. Ponomarenko (2), R.A. Greenwald (1), K. Oksavik (3), J. M. Ruohoniemi (1), J.B.H. Baker (1), L.B.N. Clausen (1)
(1) Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia, USA
(2) Institute of Space and Atmospheric Studies, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
(3) Department of Arctic Geophysics, University Centre in Svalbard, Longyearbyen, Norway

abstract. The radars of the Super Dual Auroral Radar Network (SuperDARN) employ a multi-pulse sequence in order to simultaneously resolve range and Doppler velocity. A complex autocorrelation function (ACF) is then calculated from the returns, and fitting in a routine known as fitACF is performed on the phases of the ACFs in order to resolve Doppler velocity, and to the amplitude and decay of the ACF to determine backscatter power (signal-to-noise ratio) and spectral width. A second method, called fitex2 has also been used to determine Doppler velocity, spectral width, and backscatter power from the ACFs. The Levenberg-Marquardt method has been shown to be able to correctly identify simultaneous returns from different scatterers (terrestrial surface and plasma irregularities) within the same range gate, known as mixed scatter. This method could also be applied to the fitting of returns from a single target. A comparison of ACF fitting methods) using simulated radar retu rns is performed to determine which method produces the most accurate results.

Sakaguchi KaoriNICT Japan