Patent ID: 6665622
Filing Date: 2003-12-16
Classification: G01J

Abstract:
A spectral characterization method for a signal spectrum having at least two spectrally-separated signal peaks, comprising:identifying the at least two signal peaks within the signal spectrum; measuring spectral content of the signal spectrum using a first measurement bandwidth sufficiently wide to encompass each signal peak of the at least two signal peaks; designating a signal component of the signal spectrum from the spectral content of the encompassed signal peaks as measured using the first measurement bandwidth; measuring spectral content of the signal spectrum using a second measurement bandwidth sufficiently narrow to substantially exclude capture of the at least two signal peaks within at least one interval of spectral separation between the at least two signal peaks; and designating a noise component of the signal spectrum from the spectral content measured using the second measurement bandwidth over the at least one interval of spectral separation; designating a spectral center for each identified signal peak of the at least two signal peaks according to the measured spectral content of the signal spectrum using the first measurement bandwidth; assigning a peak amplitude value to each signal peak of the at least two signal peaks; and extracting a noise level at the spectral center of the at least two signal peaks from amplitude levels at defined spectral offsets from the spectral center and within the spectral content measured using the second measurement bandwidth linearly interpolating between amplitude levels at the spectral offsets from the spectral center, wherein the defined spectral offsets correspond to a minimum amplitude level at a spectral location below each signal peak and a minimum amplitude level at a spectral location above each signal peak of the at least two signal peaks.