Complex Dielectric Measurements of Forest Fire Ash at X-Band Frequencies

Dielectric measurements of powdered forest fire ash have been investigated and presented using the Nicholson-Ross-Weir method within a WR-90 waveguide (X-band 8-12 GHz). The dielectric measurements of five samples have been outlined and taken at a room temperature of 22.8 °C. Permittivity ε for five different species has been presented within this letter. These include Eucalypt, Bracken Fern, She Oak, Wattle, and Cypress. The Eucalypt sample was tested dry and with a 30% moisture content by weight. The dry Eucalypt sample was found to have a permittivity value of approximately 2.32 ± 0.025 with a loss tangent of 0.005 ± 0.0025.

[1]  William I. Rose,et al.  Measurements of the complex dielectric constant of volcanic ash from 4 to 19 GHz , 1996 .

[2]  Duncan A. Robertson,et al.  Complex Permittivity of Volcanic Rock and Ash at Millimeter Wave Frequencies , 2011, IEEE Geoscience and Remote Sensing Letters.

[3]  A. M. Nicolson,et al.  Measurement of the Intrinsic Properties of Materials by Time-Domain Techniques , 1970 .

[4]  D. Zrnic,et al.  Radar polarimetric signatures of fire plumes in Oklahoma , 2008 .

[5]  Mal Heron,et al.  Effective complex permittivity of a weakly ionized vegetation litter fire at microwave frequencies , 2007 .

[6]  W. Weir.  Automatic measurement of complex dielectric constant and permeability at microwave frequencies , 1974 .

[7]  J. Boan,et al.  Radio Experiments With Fire , 2007, IEEE Antennas and Wireless Propagation Letters.

[8]  L. Jacobson.  IRON IN THE LEAVES AND CHLOROPLASTS OF SOME PLANTS IN RELATION TO THEIR CHLOROPHYLL CONTENT. , 1945, Plant physiology.

[9]  Noriyuki Nanba,et al.  Measurements of Dielectric Constant of Volcanic Ash Erupted From Five Volcanoes in Japan , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[10]  D. Zrnic,et al.  Polarimetric radar properties of smoke plumes: A model , 2009 .

[11]  C. P. Neo,et al.  Microwave Electronics: Measurement and Materials Characterization , 2004 .

[12]  Onisimo Mutanga,et al.  Predicting plant water content in Eucalyptus grandis forest stands in KwaZulu-Natal, South Africa using field spectra resampled to the Sumbandila Satellite Sensor , 2010, Int. J. Appl. Earth Obs. Geoinformation.

[13]  Kgakgamatso Mphale,et al.  Radiowave propagation measurements and prediction in bushfires , 2008 .

[14]  M. Odman,et al.  Combined Lidar and Radar Observations of Smoke Plumes from Prescribed Burns , 2008 .

[15]  Madison J. Post,et al.  Smoke-Column Observations from Two Forest Fires Using Doppler Lidar and Doppler Radar , 1992 .

[16]  Ari Henrik Sihvola,et al.  Analysis of a three-dimensional dielectric mixture with finite difference method , 2001, IEEE Trans. Geosci. Remote. Sens..