功率谱显示存在于每个频率点的能量。光谱相干识别信号之间的频域相关性。相干值向0趋于表明相应的频率分量是不相关的，而值向1趋于表明相应的频率分量相关。考虑两个信号和它们各自的功率谱。-A power spectrum displays the power present in each frequency. Spectral coherence identifies frequency-domain correlation between signals. Coherence values tending towards 0 indicate that the corresponding frequency components are uncorrelated while values tending towards 1 indicate that the corresponding frequency components are correlated. Consider two signals and their respective power spectra.