EI  WECC  ERCOT  QUEBEC 
FDR Map 

**The spectrum is generated by running FFT analysis against FDR/UGA frequency measurement to demonstrate the frequency oscillation. Each line (from bottomleft to upperright) represent the FFT analysis result at the corresponding timestamp. 
** The Xaxis represents spectrum frequency, range from 04.5Hz.
** The Yaxis represents the timestamp when FFT is executed. **The Zaxis represents spectrum magnitude, whose scale ranges from 0 0.014 Hz.
**Different color in this Legend are only refer to the
magnitude of the spectrum
