Analysis of the Fractal Dimension of Rain Rate Contours with Reference to Wide Area Coverage of Satellite Communications

Treating rain fields as a fractal surface raises interesting considerations for the characterization and calculation of the fractal dimension of the rain field. Data recorded at the Chilbolton Observatory in the south of England suggests that the shape of contour lines enclosing areas of rain with equal or greater than a set rain rate have a fractal dimension ~1.2 . It is shown that the accuracy of this fractal dimension is dependent on the size of the area enclosed by the contour line, due to the resolution of the radar, but is independent of the rain rate threshold.The background and application implications for communications systems at high frequencies are outlined.