Identification of the scale-free interval in HF radar sea clutter correlation dimension calculation

The fact that HF radar sea clutter has chaotic characteristics was proved many years ago. Correlation dimension is one of the key parameters to determine whether the time series are chaotic or not. We must identify the scale-free interval firstly in order to calculate it. However, the identification results of many methods aren´t accuracy enough. So, a new method, which is the fuzzy 2-means algorithm, is proposed to identify the scale-free interval of correlation integral curve in this paper. The conclusion that the method is effective is demonstrated by simulation based on the measured data of HF radar sea clutter and the data produced by several typical chaotic attractors.