Non-linearity analysis of a spectroradiometer

Abstract

Hyperspectral analysis is an important remote sensing tool. Corresponding spectrometers require accurate calibration in optical laboratories. Non-linearity and temperature dependence are important factors that degrade the calibration quality. In this paper, we report on the investigation of the non-linearity of a temperature stabilized spectroradiometer HR-1024i from Spectra Vista Corporation (SVC). The spectroradiometer is applied as transfer spectroradiometer for the radiometric calibration of air- and spaceborne imaging spectrometers. Results show signal dependent non-linearity. The non-linearity of the spectrometer’s VNIR detector in spectral range 450 − 980 nm shows a strong spectral channel dependence with maximal radiometric error of 2%. The non-linearity of the SWIR-2 detector in spectral range 1896 − 2510 nm could not be evaluated precisely due to the low signal level. This impact of non-linearity requires correction in post-data processing.