Measurement of scattering coefficient σ° of trees

Abstract

This paper describes (1) an indoor measurement method to sludy backscattering characteristics of trees and (2) the result of the measurements made on two kinds of conifers, Sugi (Japanese cedar) and Sawara (Japanese cypress), at C- and X-bands for polarization combinations of HH, VV, HV and VH. The discussions on the backscattering and penetration characteristics of the trees using the measured ground truth data indicate the usefulness of this method to study microwave signatures of trees.     

Measurement of radar backscatter from rough soil surfaces using linear and circular polarizations†

Radar backscatters from loam with a dry bulk density of 0·6g/cm³ have been measured at 9·9 GHz using both linear and circular polarizations. The sensitivity of radar return to soil moisture content has been obtained at five polarization combinations, HH, VV, HV, LR and LL (L and R denote the left-circular and the right-circular polarizations, respectively). Comparison of the moisture sensitivities shows that the sensitivity of HV is the highest among five polarizations and the sensitivity of LL is slightly higher than that of HH, VV and LR. Surface scatter theories are discussed in relation to the moisture sensitivities of five polarizations.     

Measurement of backscatter from conifers in the C and X bands

Abstract

This paper describes the microwave backscattering characteristics of three kinds of conifers, Matsu ( Japanese pine), Sugi (Japanese cedar) and Sawara (Japanese cypress), in the C and X bands for polarization combinations HH, VV, HV and VH. The measurements were made indoors using rotating-tree targets. ( i) Differences between HH and VV, (ii)the levels of the like backscatters of three conifers, and ( in) depolarization are discussed in relation to the features of canopy structure and leaf shapes. The method employed in this study will be ofuse in radar-signature studies of a wide variety of trees.