Mitigation of spectral mis-registration effects in imaging spectrometers via cubic spline interpolation

Yutao Feng,Yang Xiang

doi:10.1364/oe.16.015366

Abstract

The effects of spectral curvature (smile) on the co-registration of measured radiance spectra were analyzed for a dispersive imaging spectrometer. The spectra measured by the imaging spectrometer with spectral curvature were re-sampled using cubic spline Interpolation to mitigate the mis-registration of spectral radiance measurement. After correction, the co-registration of measured radiance spectra is distinctly improved.

Highlights

Imaging spectrometers measure spectrum of each spatial scene element in an image
When the spectral offsets are no more than 5%Δλ, the mis-registration of the spectral radiance measurement can be mitigated well via cubic spline interpolation
Cubic spline interpolation can effectively correct the errors in the measured radiance and mitigate the mis-registration of spectral radiance measurement

Summary

Introduction

Imaging spectrometers measure spectrum of each spatial scene element in an image. It is necessary to keep the co-registration of the measured spectra for all scene elements. The spectral radiance measured by the imaging spectrometer with spectral curvature was interpolated via Cubic Spline Interpolation (CSI) to mitigate the mis-registration of the measured radiance spectra. If there were no spectral curvature, there would be the same center wavelength for all pixels in the same cross-track array j on the detector plane. While if there were spectral curvature on the detector plane, there would be certain center wavelength offset δm,j of the pixel (i+m,j) relative to the pixel (i,j) (See Fig. 1), λi+m,j=λi,j+δm,j. 3. Correction In order to mitigate the mis-registration of measured radiance spectra, the spectral radiance measured by the detector pixels in the column i+m was re-sampled to acquire the approximations of the measured radiance corresponding to the center wavelengths of the detector pixels in the column i. The mis-registration of spectral radiance measurement can be neglected

Discussions

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Conclusions