Patent ID: 8121815

Claim:
A noise separating apparatus that separates a probability density function of a predetermined noise component from a probability density function of a signal under test, comprising: a domain transforming section that is supplied with the probability density function of the signal under test and transforms the probability density function into a spectrum in a predetermined variable axis; a standard deviation computing section that computes standard deviation of a random component of noise contained in the signal under test from a magnitude of a predetermined variable component, in the variable axis, in a main lobe of the spectrum, wherein the standard deviation computing section computes the standard deviation of the random component, based on the magnitude of the predetermined variable component in the main lobe of the spectrum and a magnitude of the predetermined variable component in a main lobe of a spectrum corresponding to a deterministic component of noise contained in the probability density function; and a peak to peak value detecting section that detects a peak to peak value of the deterministic component based on a value, in the variable axis, of at least one null that is included in a predetermined number of nulls which are selected from nulls included in the spectrum starting from a null whose value in the variable axis has the smallest absolute value.