ISSN:
1572-9559
Keywords:
absorption cross-section
;
measurement
;
canopy
;
stalk
;
resonator
;
millimeter waves
Source:
Springer Online Journal Archives 1860-2000
Topics:
Physics
Notes:
Abstract A new millimeter wave resonant method for determination of absorption cross-section of vegetation stalks is given. The method is developed for study of vegetation stalks absorption cross-section as a function of their moisture content, orkR parameter (k is a wave number, R is a stalk radius) in millimeter wavelengths band. ModesE 01p of a cylinder resonator are employed for such measurements. Dielectric permittivity and loss tangent of a sample can be found by measuring a frequency shift andQ- factor changes of the resonator. Absorption cross-section of a sample is then calculated using a formula obtained in our theoretical study. This formula can be written analytically as a result of rigorous solution of the related diffraction problem (scattering of a plane electromagnetic wave by cylinder with complex dielectric permittivity if stalk radius is less then 0.5 mm for the wavelength of 8 mm). Results of this investigation may be used in creating electrodynamical models of media containing cylindrical stalks of plants, in direct measurements of some canopy parameters, transmission properties measurements of vegetation canopies etc.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02088913
Permalink
