Advancing NASA's AirMOSS P-Band Radar Root Zone Soil Moisture Retrieval Algorithm via Incorporation of Richards' Equation

Morteza Sadeghi 1,*, Alireza Tabatabaeenejad 2, Markus Tuller 3, Mahta Moghaddam 2 and Scott B. Jones 1 1 Department of Plants, Soils and Climate, Utah State University, Logan, UT 84322, USA; [email protected] 2 Ming Hsieh Department of Electrical Engineering, University of Southern California, Los Angeles, CA 90089, USA; [email protected] (A.T.); [email protected] (M.M.) 3 Department of Soil, Water and Environmental Science, The University of Arizona, Tucson, AZ 85721, USA; [email protected] * Correspondence: [email protected]; Tel.: +1-435-554-5369