Multi-frequency and polarimetric measurements of perturbed water surface microwave reflective and emissive characteristics by C-, and Ku-band combined scatterometric-radiometric systems

A New Approach in Hail Prevention Technique for a Locally Restricted Area

“…In Figure 5 a curve of "alert" threshold's frequency dependence is presented as well, estimated and approximated from the results of theoretical and experimental researches [18]- [23]. Radiometric contrasts of Figure 5 are given in Kelvin.…”

“…In Figure 5 frequency dependences of "maximum" and "minimum" threshold levels are presented, where the curve of "minimum" threshold level corresponds to radiometric contrasts frequency dependence of cumulonimbus caused a rainfall with rare hail stones. "Minimum" values of radiometric contrasts of Figure 5 were estimated and approximated from the results of multi-frequency and dual polarization (vertical and horizontal) radiometric measurements carried out under elevation angles 20˚ and 30˚ of sensing [18]- [24] and from the known theory of passive microwave (radiometric) remote sensing. Theoretical approximations show that these curves are acceptable for elevation angles from the interval 0˚ -30˚ as well.…”