功率谱是功率谱密度函数的简称，它定义为单位频带内的信号功率。它表示了信号功率随着频率的变化情况，即信号功率在频域的分布状况。-Spectral analysis or Spectrum analysis is analysis in terms of a spectrum of frequencies or related quantities such as energies, eigenvalues, etc. In specific areas it may refer to: