Absorption Line Evaluation Methods for Wavelength Standards

Published

July 22, 1998

Author(s)

C. J. Zhu, Leonard M. Hanssen

Abstract

Two methods for absorption line (peak) evaluation based on center of gravity (CG) calculations are described and compared using spectra of the NIST standard reference material (SRM) 1921(a) characterization measurements. These methods are (1) calculating the CG of 50% of the absorption line and (2) an extrapolated center of gravity (ECG) method designed to determine the line minimum (peak maximum) location. Important parameters used in both methods are evaluated. The importance of the spectral data spacing on the accuracy of the CG calculation is examined in detail and quantified for the 1921a lines. The effects of the range of data as well as the fitting routine used in the extrapolation process (in the ECG method) on the final line minimum are examined. A comparison of the absorption line values determined from the SRM 1921(a) spectra by the two methods is presented.

Proceedings Title

Proceedings of the International Society for Optical Engineering

Conference Dates

July 19-22, 1998

Conference Title

International Society for Optical Engineering

Pub Type

Conferences

Keywords

center of gravity method, data spacing, extrapolated center of gravity, extrapolated peak minimum, FT-IR, peak finding, peak shift, wavenumber standard, weighted Chi square fit

Citation

Zhu, C. and Hanssen, L. (1998), Absorption Line Evaluation Methods for Wavelength Standards, Proceedings of the International Society for Optical Engineering (Accessed July 22, 2025)