Fig. 7
From: Ground-based VLF wave intensity variations investigated by the principal component analysis
![Fig. 7](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs40623-022-01588-4/MediaObjects/40623_2022_1588_Fig7_HTML.png)
First three principal component basis vectors obtained for individual frequency spectra
From: Ground-based VLF wave intensity variations investigated by the principal component analysis
First three principal component basis vectors obtained for individual frequency spectra