Hua Su Xin Yang Xiao-Hai Yan Estimating Ocean Subsurface Salinity from Remote Sensing Data by Machine Learning. 8139-8142 2019 IGARSS https://doi.org/10.1109/IGARSS.2019.8898899 conf/igarss/2019 db/conf/igarss/igarss2019.html#SuYY19