A K-band microwave measuring system for the analysis of tree stems

Pekka Eskelinen, Harri Eskelinen
2000 Silva Fennica  
Eskelinen, P. & Eskelinen, H. 2000. A K-band microwave measuring system for the analysis of tree stems. Silva Fennica 34(1): 37-45. The internal structure of growing trees and freshly cut logs can be characterized in real time by analysing the transmission and reflection of Ku-or K-band microwave energy injected with a horizontal polarization towards the material. Information about the moisture content, material bends, number and location of knots and sections of spoiled wood e.g. due to
more » ... e.g. due to insects can be gathered in real time. Most sensitive test parameters are attenuation, group delay and the rotation of a linearly polarized wavefront. A simultaneous recording of reflection reduces errors caused by non-significant surface deformations. The spatial resolution, humidity equalization and noise immunity can be improved by applying a wideband frequency modulation. Commercial building blocks supplemented with a special antenna arrangement give possibilities also for the rough harvester environment.
doi:10.14214/sf.643 fatcat:ernismj6w5axrlbcbga34wjslq