Noise-equivalent change in radiance for sampling noise in a double-sided interferogram

Area of Science:

• Spectroscopy
• Radiometric measurements
• Optical physics

Background:

• The noise-equivalent change in radiance (NEdN) is a critical metric for assessing spectral measurement sensitivity.
• Existing NEdN formulas based on sampling noise perform well for isolated spectral features but struggle with broad, continuous spectra.

Purpose of the Study:

• To develop and validate a modified formula for calculating the noise-equivalent change in radiance (NEdN) that accurately accounts for sampling noise.
• To address limitations of previous NEdN formulas when analyzing broad radiance spectra.

Main Methods:

• The study involved modifying the existing noise-equivalent change in radiance (NEdN) formula.
• The modified formula was applied to double-sided interferograms of various radiance spectra, including Planck blackbody curves and spectra with isolated emission lines.
• Performance was evaluated by comparing results from the original and modified formulas.

Main Results:

• The original noise-equivalent change in radiance (NEdN) formula showed inaccuracies when applied to broad, slowly varying radiance spectra like Planck blackbody curves.
• The modified noise-equivalent change in radiance (NEdN) formula demonstrated accurate performance across both isolated emission line spectra and broad radiance spectra.
• The enhanced formula provides reliable noise estimations for diverse spectral characteristics.

Conclusions:

• A modified noise-equivalent change in radiance (NEdN) formula effectively overcomes the limitations of previous methods for sampling noise.
• This improved formula enhances the accuracy of radiometric measurements, particularly for complex spectral distributions.
• The validated approach is crucial for precise spectral analysis in various scientific and technical applications.