Changes to this version include: - An improved calibration methodology was applied to Level-1 brightness temperatures, which uses: * the internal instrument reference load (instead of the global ocean as in V4) * deep space measurements during monthly cold sky maneuvers and special cold sky maneuvers with stable open-ocean background to concurrently retrieve all calibration parameters * a longer temporal baseline of cold sky records. For the full major and minor version history, go to https://nsidc.org/data/smap/version-history