Chen Xu, Xiang Yang, Feng Yu-Tao
State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun 130033, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2011 Apr;31(4):1147-50.
Spectral curvature destroys the co-registration of the spectra measured by dispersion imaging spectrometer. Using interpolation to re-sample the measured spectra at the non-offset mid-wavelengths can mitigate the spectral misregistration. It is very important to select an optimum interpolation method. The performances of six common interpolation methods are evaluated by comparing the residual errors in the corrected spectral radiance. The results indicate that, four-point cubic Lagrange interpolation and cubic spline interpolation are better than other four interpolation methods (linear Interpolation, three points quadratic polynomial interpolation, five points four-order Lagrange interpolation and cubic Hermite interpolation). For spectral offset of 10% deltalambda (deltalambda = 5 nm), the normalized errors in measured spectral radiance is PV = 0.06, that is reduced to PV < 0.022 after interpolation with cubic Lagrange interpolation or cubic spline interpolation, but for other four methods they are PV > 0.035. Furthermore, for lower spectral resolution (deltalambda > 5 nm), cubic Lagrange interpolation is a little better than cubic spline interpolation; while for higher spectral resolution (deltalambda < 5 nm), cubic spline interpolation is a little better.
光谱曲率破坏了色散成像光谱仪所测光谱的配准。通过在无偏移的中波长处对测量光谱进行插值重采样，可以减轻光谱配准误差。选择最佳的插值方法非常重要。通过比较校正后的光谱辐射率中的残余误差，评估了六种常用插值方法的性能。结果表明，四点三次拉格朗日插值和三次样条插值比其他四种插值方法（线性插值、三点二次多项式插值、五点四阶拉格朗日插值和三次埃尔米特插值）更好。对于10%的δλ（δλ = 5 nm）光谱偏移，测量光谱辐射率中的归一化误差为PV = 0.06，在用三次拉格朗日插值或三次样条插值后降至PV < 0.022，但对于其他四种方法，它们的PV > 0.035。此外，对于较低的光谱分辨率（δλ > 5 nm），三次拉格朗日插值比三次样条插值稍好；而对于较高的光谱分辨率（δλ < 5 nm），三次样条插值稍好。
