Tracking subpixel-scale sastrugi with Advanced Land Imager

High radiometric resolution imagery from the Advanced Land Imager (ALI) can detect the spatial reflectance variations associated with sastrugi (snow dunes) on ice sheets. This is shown, in theory, by considering the appropriate SNR ratio of ALI as compared with eight-bit optical sensors and, in practice, with multitemporal ALI imagery. Comparison of ALI imagery spanning 7.5 months also shows that the reflectance pattern associated with sastrugi can persist over this interval offering the potential of their use for measuring ice sheet velocity in uncrevassed regions.