宽波段单色仪多级谱高精度波长定标

High-Precision Wavelength Calibration of Wide-Band Monochromator

通常利用单色仪输出的单色光对空间遥感光谱仪进行波长定标。提出以空间遥感光谱仪的置信度为标准,来评价宽波段单色仪高精度波长定标精度的方法。通过对仪器精度的分析,分别求出单色仪的波长的重复性误差和偏差。应用高压汞灯的本征谱和光栅衍射多级谱作为定标谱线,避免更换灯源带来的误差。通过粗细定标相结合的方法,缩短扫描时间,并且运用高斯拟合对波峰进行精确定位,缩小误差。最后利用高次拟合得到的关系式,测出单色仪波长精度,计算出空间遥感光谱仪定标的置信度。以1.5 M单色仪为例,单色仪在200～840nm波段内波长精度±0.016nm,则空间遥感光谱仪的波长精度达到±0.050nm的置信度为99.82%。

Usually the monochromator is used to output monochromatic light to calibrate the space remote sensing spectrometer. In the present paper, the confidence of space remote sensing spectrometer is used as a standard to evaluate the preeision of wideband monochromator wavelength calibration. Through analysis of the accuracy of the instrument, the monoehromator wavelength repeatability error and deviations was obtained respectively. And the intrinsic spectrum of the high pressure mercury lamp and the grating diffraction was used as calibration lines to avoid the error caused by replacing the light source. Through the special method of wavelength calibration to shorten the scan time, the Gaussian fitting was used to look for peaks of wavelength to reduce error. Finally, the relationship derived from polynomial fitting to measure the exact wavelengths＇ aceuraey of the monochromator and calculate the calibration confidence of the space remote sensing spectrometer. Using this method, we can make wavelength accuracy of the 1.5 M monoehromator with wavelength band from 200 to 840 nm to reach to ±0. 016 nm, then the confidence of the space remote sensing spectrometer can reach to 99.82%.