Algorithm Of Feature Parameters Of Solar Radio Burst Fiber Structures

This thesis mostly study the calculation of feature parameters of fiber fine structures in solar radio bursts. Firstly the dynamic spectrum of fiber structure is processed using wavelet transform. The fiber fine struscture is generally superposed on total solar radio burst, but we are interested more in the fine structure. So we dispose of the backgroud of the total radio burst to pick-up the fiber structures. Wavelet transform can distill the signal in different frequency due to its Muti-resolution character. By doing five class wavelet transform to the original spectrum and reforming original image by low-frequency part, we can get the background information. After subtraction of the backgroud from the original spectrum and throshold processing, the fiber structures can be seperated exactly.The data points in every channel of the spectrum after wavelet transform processing are seperated to several continuous segments, which represent the fiber structure information in this channel. Thus we get instantaneous bandwidth of the fiber structures. Then the methods of Cubic Spline Interpolation or Generalized Extented Interpolation are applied to fit the intensity-time relation in every continuous segment, in order to determine occuring time of every intensity maxima. Record the channel number and the time of the intensity maxima forming the fiber structures.Finally the drift rate is found by Linear Regression. The other parameters such as duration, bandwidth and relative bandwidth of the fiber structures are also gotten. Specifically the algorithm is used to calculate the feature parameters for the radio fiber everts on 21-Apirl-2002, and the relevant histogram are drawn out.