The opacity of clouds is the main problem for optical and thermal space-borne sensors. like the Moderate-Resolution Imaging Spectroradiometer (MODIS). Especially during polar nighttime. the low thermal contrast between clouds and the underlying snow/ice results in deficiencies of the MODIS cloud mask and affected products. https://www.roneverhart.com/Under-Armour-Hustle-5-0-TEAM-Backpack/