739-3 Assessing the Susceptibility of Sensors to Local Property Variability.

See more from this Division: S01 Soil Physics
See more from this Session: Symposium --Seeing Into the Soil: Noninvasive Characterization of Biophysical Processes in the Soil Critical Zone: II/Div. S01 Business Meeting

Wednesday, 8 October 2008: 1:30 PM
George R. Brown Convention Center, 361AB

John Knight, Queensland Univ. of Technology, Brisbane, Australia and Ty Ferre, PO Box 210011, Univ. of Arizona, Tucson, AZ
Abstract:
We consider the general problem of spatial averaging by sensors. Specifically, we consider the dependence of an instrument response on the local calibration relationship, the spatially variable sensitivity of the instrument, and the spatially heterogeneous distribution of the property of interest. Our objective is to show that the effects of each of these relationships can be calculated for simple checkerboard patterns. Further, that the response of an instrument to more complex spatial distributions can be understood by combining the responses to multiple checkerboards through the use of two-dimensional Fourier transforms. This will allow for quantification of the sensitivity of sensors to sub-sample-volume variability, which can be used to predict the uncertainty of indirect measurements as a function of the spatial scale of variability of the property of interest. We show this for several instruments with differing spatial sensitivity distributions with simple but realistic Fourier transforms.

See more from this Division: S01 Soil Physics
See more from this Session: Symposium --Seeing Into the Soil: Noninvasive Characterization of Biophysical Processes in the Soil Critical Zone: II/Div. S01 Business Meeting