Version 4 of the SMAP Level‐4 Soil Moisture Algorithm and Data Product oleh Rolf H. Reichle, Qing Liu, Randal D. Koster, Wade T. Crow, Gabrielle J. M. De Lannoy, John S. Kimball, Joseph V. Ardizzone, David Bosch, Andreas Colliander, Michael Cosh, Jana Kolassa, Sarith P. Mahanama, John Prueger, Patrick Starks, Jeffrey P. Walker