| 2010 | IGARSS | Surface reference normalized radar cross section over land for the improvement of the TRMM PR algorithm. | Ken'ichi Okamoto, Jun Komukai, Shoichi Shige, Takeshi Manabe |
| 2006 | IGARSS | Suppression of Surface Clutter Interference with TRMM Precipitation Radar Observation. | Tetsuya Tagawa, Ken'ichi Okamoto, Hiroshi Hanado, Toshiaki Kozu |
| 2006 | IGARSS | Development of Over-ocean SSM/I Rain Retrieval Algorithm in the GSMaP Project. | Hiroshi Hashizume, Takuji Kubota, Kazumasa Aonashi, Shoichi Shige, Ken'ichi Okamoto |
| 2005 | IGARSS | Development and observation of the broad-band radar for meteorological application. | Kazushi Monden, Tomoaki Mega, Tomoo Ushio, Ken'ichi Okamoto |
| 2005 | IGARSS | The global satellite mapping of precipitation (GSMaP) project. | Ken'ichi Okamoto, Tomoo Ushio, Toshio Iguchi, Nobuhiro Takahashi, Koyuru Iwanami |
| 2005 | IGARSS | Measurement of scattering properties of vegetation at Ka-band by 35GHhz polarimetric scatterometer. | Tetsuya Tagawa, Ken'ichi Okamoto, Tomoo Ushio |
| 2005 | IGARSS | Sampling simulation for estimating the sampling error of space-time average rain rate for TRMM and GPM mission. | Yasuhisa Iida, Ken'ichi Okamoto, Tomoo Ushio, Riko Oki |
| 2004 | IGARSS | Suppression of surface clutter interference with precipitation measurement from space by the Dual frequency Precipitation Radar. | Tetsuya Tagawa, Ken'ichi Okamoto, Hiroshi Hanado, Toshiaki Kozu |
| 2004 | IGARSS | Measurement of scattering coefficient dependence on soil moisture content and surface roughness by 35 GHz polarimetric scatterometer. | Tetsuya Tagawa, Ken'ichi Okamoto, Akira Higuchi, Tomoo Ushio, Hiroshi Hanado |
| 2003 | IGARSS | Calculations of surface clutter interference with precipitation measurement from space by 35.5 GHz radar for Global Precipitation Measurement Mission. | Tetsuya Tagawa, Ken'ichi Okamoto |
| 2003 | IGARSS | Sampling simulation of five sun synchronous orbit satellites' group and TRMM rainfall estimation using radar-AmeDAS composites. | Yasuhisa Iida, Ken'ichi Okamoto |