The link between observed signal and physical properties is the dielectric constant. Comparing to the dielectric constants of dry biomass and soil particles, water shows 10 times higher dielectric permittivity. The key part of our observation operator is the implementation of effective dielectric constants of these complex components applying mixing approach. Dielectric mixing approach consistently decomposes the optical properties of soil, biomass, water and air into finer elements. The observation operator is examined with passive microwave remote sensing data (L,C and X-band observations) and in-situ measurements (canopy type, soil texture, soil temperature and soil water). The further development of the operator will be performed for active microwave and thermal infrared as a hyper spectral observation operator including atmospheric layer containing absorbing gases.