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Cross-spectral Analysis. Investigates the dependence or relationship between two time series. Begin by reviewing cross-correlation function – how similar two time series x , y are. L = lag N = # of elements in time series. Covariance or cross-covariance. Cross-correlation.
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Cross-spectral Analysis Investigates the dependence or relationship between two time series. Begin by reviewing cross-correlation function – how similar two time series x , y are L = lag N = # of elements in time series Covariance or cross-covariance Cross-correlation -1 <ψxy< 1
Current velocity and water level (red) in Ensenada de La Paz Year Day
Cross-correlation between current velocity and water level in Ensenada de La Paz
Cross-correlation between current velocity and water level in Ensenada de La Paz
A generalization of: Complex Cross-correlation * is the complex conjugate
Complex Cross-correlation between vectors at 2 depths in Ensenada de La Paz w1w2 L
Complex Cross-correlation between vectors at 2 depths in Ensenada de La Paz
Complex Cross-correlation between vectors at 2 depths in Ensenada de La Paz
Coherence spectrum (coherency) < > = running mean X is the Fourier Transform = 0.1, 0.05, 0.01
Current velocity and water level (red) in Ensenada de La Paz Year Day
Coherence squared window size= 2 cpd = 0.1, 0.05, 0.01
99% Coherence 2 95% Window size= 10 Phase (deg)
Coherence 2 99% 95% Window size= 24 Phase (deg)
99% Coherence 2 95% Window size= 10 Phase (deg)
99% Coherence 2 95% Window size= 10 Phase (deg)
Coherence 2 99% 95% Window size= 24 Phase (deg)
Coherence 2 99% 95% Window size= 24 Phase (deg)