Improvements to the calibration of a NEO HySpex VNIR-1600

A HySpex VNIR-1600 sensor, built by NEO and operated by DLR, was extensively characterized in DLR's calibration home base (CHB) and with PTB's PLACOS setup over the course of two years. The generated data significantly extends the characterization performed by the manufacturer, thus allowing to extend the original raw data calibration method. The improvements make use of the radiometric characterization with respect to a SI-traceable radiometric standard, characterization of the keystone and smile optical distortions, characterization of a radiometric nonlinearity and of spatial and spectral in-band stray light. While descriptions of the first two measurements were already published, this talk will present the characterization of nonlinearity and stray light. This extensive effort in characterization is justifiable and required, as data stemming from this instrument will, besides regular remote sensing applications, be used to validate satellite missions and for simulations of the EnMAP mission. Meaning that, if the validation data is incorrect, artefacts can be easily introduced to the satellite instrument's data or analyses based thereupon. Specifcally, the contribution of stray light is assessed on the example a hyperspectral scene of lake Starnberg. As the contributions turn out to be rather significant, and the stray light levels in the characterized sensor are apparently quite low, this means that, for many pushbroom instruments, the influence of stray light is likely to be of a similar magnitude