POWER-SPECTRUM ANALYSIS OVER LARGE RANGES OF FREQUENCY

Abstract

It is shown that a spectrum covering a large range of frequencies can be found by superposing estimates of spectra of means over periods of different lengths. The method is illustrated by the power spectrum of temperature at University Park, Pennsylvania, covering periods from 2 to 7300 days. The spectrum is characterized by a major peak at four days and several minor ones, the reality of which is uncertain.