A comparative study of three techniques for using the spectral matrix in wave analysis
Article first published online: 7 DEC 2012
Copyright 1976 by the American Geophysical Union.
Volume 11, Issue 10, pages 833–845, October 1976
How to Cite
1976), A comparative study of three techniques for using the spectral matrix in wave analysis, Radio Sci., 11(10), 833–845, doi:10.1029/RS011i010p00833., , and (
- Issue published online: 7 DEC 2012
- Article first published online: 7 DEC 2012
- Manuscript Received: 7 NOV 1975
Digital power spectral analysis and coherency analysis are powerful techniques for studying ultra-low-frequency (ULF) waves in the earth's magnetosphere. Wave polarization parameters provided by these techniques are important in the development of theoretical models for wave generation. Because of this, it is important to understand the capabilities of the digital analysis techniques. Three different techniques of using the spectral matrix to do wave analysis have been presented in the literature. Because data for wave studies involve measurement in arbitrary coordinate systems, it is necessary to transform the spectral matrix to the principal plane of the wave before coherency analysis can be performed. The fundamental differences in the three techniques lie in how they determine the transformation to the principal plane. A comparative study of these three techniques was done using simulated data involving known wave and noise properties and real ULF wave event data from the geosynchronous satellites ATS 1 and ATS 6. In general, the quality of performance of the three different techniques on both simulated and real wave events was approximately the same.