Generation of SMAP 9 KM soil moisture using a spatio-temporal information fusion model

Soil Moisture Active Passive (SMAP) satellite mission, launched on Jan. 31, 2015, can provide a 9 km soil moisture product globally by merging passive and active observations. However, the radar sensor of SMAP was failed since Jul. 7, 2015 and SMAP 9 km SM product (SMAP_AP) is only available for 85 days. To ameliorate the vacancy of SMAP_AP, a spatio-temporal fusion model STNLFFM combined with the SMAP 36 km soil moisture product (SMAP_P) is utilized to generate 9 km soil moisture SM product (SMAP_F). Generation of SMAP_F was implemented over one year from Apr. 13, 2015 to Apr. 12, 2016 in the paper. Then SMAP_F was evaluated by SMAP_AP and in-situ soil moisture from international soil moisture network. It is revealed that the STNLFFM can be taken as an effective method for SMAP 9 km soil moisture generation.