Research on the accuracy of spectral calibration using atmospheric absorption features with different water vapor contents

Abstract

Nowadays, spectrometers are being increasingly used in the remote sensing of the earth system processes and they can be well conducted field spectral calibrated by using absorption features of atmospheric profile. The spectral calibration accuracy of an ASD spectrometer in different atmospheric conditions is analyzed in this paper. First of all, set the atsensor spectral radiance spectrum as the reference spectral curve, which is generated by the MODTRAN5 radiative transfer model outputs convolved with the spectral response function of each channel. The results can be totally different when input different water vapor contents. Meanwhile, under the same atmospheric conditions (the same observation target, the sun elevation angle, azimuth, aerosol distribution, composition and concentration distribution of atmosphere..etc. ), the diffuser whiteboard is measured by the ASD spectrometer to acquire observed spectral curve. The best spectral matching algorithm is used to compare the observed spectrum with the reference one. Central wavelength of the ASD is obtained by calculating the results of matching spectrum shifts within feature spectrum range. Finally, quantitative analysis and calculation about the effect on the accuracy of instrument spectral calibration with different water vapor contents is presented.