ATBDsCollectionsSMAPDataset Id and VersionSPL4SMAU1SPL4SMGP1SPL4SMLM1SPL4SMAU2SPL4SMAU3SPL4SMAU4SPL4SMAU5SPL4SMLM2SPL4SMLM3SPL4SMLM4SPL4SMLM5SPL4SMGP5SPL4SMGP6SPL4SMLM6SPL4SMAU6SPL4SMAU/SMGP/SMLM Algorithm Theoretical Basis Document [2014]Data Programnasa_nsidc_daac