Characterizing and correcting Hyperion detectors using ice-sheet images

Two Hyperion images of the Greenland ice sheet are used to characterize errors in the visible near-infrared (VNIR) and shortwave infrared (SWIR) detector arrays of Hyperion. Spatial variability in detector output is seen in both arrays and, in both cases, is largest at the shorter wavelengths and decreases as wavelength increases. Standard deviations of the maximum variability are 40 digital numbers (DNs) for the VNIR array and 123 DNs for the SWIR array. Based on a single pair of images, temporal stability is nearly as large and exhibits the same spectral characteristics of large variability at shorter wavelengths and decreasing variability with increasing wavelength. The uniformity and stability of the ice-sheet surface enables a detailed characterization and emphasizes the utility of using ice sheets as targets to achieve on-orbit sensor characterization.