Most of the microwave (MW) radiometers already launched t o the space work at the frequencies below 100 GHz.The major limit to the applica tion of those radiometric measurements is their very poor spatial resolution.Alo ng with the advances in millimeter wave(MMW),sub millimeter wave(SMMW),and infr ared technologies,the necessarily and feasibility of using the EHF(extremely high frequency),MMW,and SMMW for remote sensing of Earth environment have been reco gnized.This paper reviews the works on