Determination of log moisture content using ground penetrating radar (GPR). Part 2. Propagation velocity (PV) method

Abstract Log moisture content (MC) has been determined based on the propagation velocity (PV) of ground penetrating radar (GPR) signals. This approach is based on measuring the travel time of the GPR signal through the log, from which its PV and the apparent log dielectric permittivity can be retrieved. Linear regression between the log dielectric permittivity and MC was established for each of the investigated wood species (quaking aspen, balsam poplar, and black spruce), log state (thawed and frozen), and direction of measurement [on the log cross-section (CS) and through the bark (TB)]. CS and TB measurements led to different results depending on the log state and wood species. Linear models with different slopes were found for thawed (slope=6.4–9.8) and frozen (slope=12–29) logs due to the difference in the dielectric properties of the frozen and unfrozen water in wood. The models for quaking aspen and balsam poplar were very similar to each other and differed from that of black spruce in terms of slopes and intercepts. Generally, the PV method leads to poorer log MC prediction accuracy than the partial least squares method presented in Part 1 of this study.

[1]  Mandy Berg,et al.  Nondestructive Characterization and Imaging of Wood , 2003, Holz als Roh- und Werkstoff.

[2]  Lihai Wang,et al.  Modeling temperature effect on dynamic modulus of elasticity of red pine (Pinus resinosa) in frozen and non-frozen states , 2015 .

[3]  F. Coppens,et al.  First arrival picking on common-offset trace collections for automatic estimation of static corrections , 1985 .

[4]  Nils Lundgren.  Modelling microwave measurements in wood , 2005 .

[5]  Sebastiano Foti,et al.  Laterally constrained inversion of ground roll from seismic reflection records , 2009 .

[6]  Fawwaz T. Ulaby,et al.  Microwave Dielectric Properties of Plant Materials , 1984, IEEE Transactions on Geoscience and Remote Sensing.

[7]  Finite element modeling (FEM) simulation of interactions between wood and microwaves , 2006, Journal of Wood Science.

[8]  William Salas,et al.  Temporal and Spatial Variations in Dielectric Constant and Water Status of Dominant Forest Species from New England , 1994 .

[9]  M. Stevens,et al.  Dielectric properties of softwood species at microwave frequencies , 1984, Wood Science and Technology.

[10]  Michel Chouteau,et al.  Assisted traveltime picking of crosshole GPR data , 2009 .

[11]  N. Diamanti,et al.  Effect of wood log shape on moisture content measurement using GPR , 2014, Proceedings of the 15th International Conference on Ground Penetrating Radar.

[12]  Brigitte Leblon,et al.  Determination of log moisture content using early-time ground penetrating radar signal , 2015 .

[13]  W. M. Daud,et al.  Dielectric and ultrasonic properties of rubber wood. Effect of moisture content grain direction and frequency , 1998, Holz als Roh- und Werkstoff.

[14]  Grigoriy I. Torgovnikov,et al.  Dielectric Properties of Wood and Wood-Based Materials , 1993, Springer Series in Wood Science.

[15]  Tadashi Yamada,et al.  Anisotropy of Dielectric Constant in Coniferous Wood , 1978 .

[16]  A. P. Annan,et al.  Measuring Soil Water Content with Ground Penetrating Radar: A Review , 2003 .

[17]  Ross Ihaka,et al.  Gentleman R: R: A language for data analysis and graphics , 1996 .

[18]  Danilo R. Velis,et al.  Automatic first-breaks picking: New strategies and algorithms , 2010 .

[19]  H. F. Hodges,et al.  Modeling Temperature Effects on Cotton Internode and Leaf Growth , 1997 .

[20]  K. Khalid,et al.  Temperature dependence of the dielectric properties of rubber wood , 2001 .

[21]  K. Khalid,et al.  Dielectric properties of rubber wood at microwave frequencies measured with an open-ended coaxial line , 1997 .

[22]  Hamiyet Sahin,et al.  Dielectric properties of hardwood species at microwave frequencies , 2004, Journal of Wood Science.

[23]  R. Gerhardt,et al.  Dielectric characterization of wood and wood infiltrated with ceramic precursors , 1996 .

[24]  Tadashi Yamada,et al.  The Dielectric Properties of Wood VI : On the Dielectric Properties of the Chemical Constituents of Wood and the Dielectric Anisotropy of Wood , 1972 .

[25]  Patrick Perré,et al.  Complex Dielectric Properties of the Sapwood of Aspen, White Birch, Yellow Birch, and Sugar Maple , 2008 .

[26]  Brigitte Leblon,et al.  Determination of log moisture content using ground penetrating radar (GPR). Part 1. Partial least squares (PLS) method , 2015 .

[27]  Yury Shramkov,et al.  Modeling the dielectric properties of wood , 2006, Wood Science and Technology.

[28]  F. García-García,et al.  Estudio de la variación del contenido de humedad en el Pinus Pinaster Ait por medio de la técnica no destructiva del georradar , 2011 .

[29]  A. P. Annan,et al.  Electromagnetic determination of soil water content: Measurements in coaxial transmission lines , 1980 .

[30]  Johan Alexander Huisman,et al.  Measuring soil water content with ground penetrating radar , 2003 .

[31]  John C. Bancroft,et al.  Time Picking on Noisy Microseismograms , 2010 .

[32]  A. Paz,et al.  Influence of Temperature in Radio Frequency Measurements of Moisture Content in Biofuel , 2006, 2006 IEEE Instrumentation and Measurement Technology Conference Proceedings.

[33]  Yury Shramkov,et al.  Measuring the dielectric properties of wood at microwave frequencies , 2005, Wood Science and Technology.

[34]  Misato Norimoto,et al.  Dielectric Properties of Wood , 1976 .