EarthRef.org Reference Database (ERR)
Development and Maintenance by the EarthRef.org Database Team

Detailed Reference Information
Drevin & Stoker 2003
Drevin, G.R. and Stoker, P.H. (2003). Determining riometer quiet day curves 2. Derivation of filter cutoff frequencies. Radio Science 38: doi: 10.1029/2001RS002538. issn: 0048-6604.

A method for the determination of riometer quiet day curves which is based on the filtering of a discrete two-dimensional function or matrix has been proposed. The two dimensions of the matrix are siderial time and day number, with each row of the matrix representing one siderial day. The filtering is done in the Fourier domain using a low-pass filter. With a low-pass filter the low frequency Fourier coefficients are retained, while the high frequency Fourier coefficients are discarded. The highest Fourier coefficient that is retained is the cutoff frequency of the filter. In this paper the filter cutoff frequencies are derived directly from the antenna reception pattern as well as from the data itself. A number of methods can be used to infer a cutoff frequency from the data; however, only a number of entropy based methods are investigated in this paper.

BACKGROUND DATA FILES

Abstract

Keywords
Radio Science, Radio wave propagation, Radio Science, Tomography and imaging, Radio Science, Signal processing
Journal
Radio Science
Publisher
American Geophysical Union
2000 Florida Avenue N.W.
Washington, D.C. 20009-1277
USA
1-202-462-6900
1-202-328-0566
service@agu.org
Click to clear formClick to return to previous pageClick to submit