Validation of ground penetrating radar full-waveform inversion for field scale soil moisture mapping

Abstract

Ground penetrating radar (GPR) is an efficient method for soil moisture mapping at the field scale, bridging the scale gap between small-scale invasive sensors and large-scale remote sensing instruments. Nevertheless, commonly-used GPR approaches for soil moisture characterization suffer from several limitations and the determination of the uncertainties in GPR soil moisture sensing has been poorly addressed. Herein, we used an advanced proximal GPR method based on full-waveform inversion of ultra-wideband radar data for mapping soil moisture and uncertainties in the soil moisture maps were evaluated by three different methods. First, GPRderived soil moisture uncertainties were computed from the GPR data inversion, according to measurements and modeling errors and to the sensitivity of the electromagnetic model to soil moisture. Second, the reproducibility of the soil moisture mapping was evaluated. Third, GPR-derived soil moisture was compared with ground-truth measurements (soil core sampling). The proposed GPR method appeared to be highly precise and accurate, with spatially averaged GPR inversion uncertainty of 0. and an uncertainty of 0.0233 m 3 m −3 when compared with ground-truth measurements. These uncertainties were mapped and appeared to be related to some local model inadequacies and to small-scale variability of soil moisture. In a soil moisture mapping framework, the interpolation was found to be the determinant source of the observed uncertainties. The proposed GPR method was proven to be largely reliable in terms of accuracy and precision and appeared to be highly efficient for soil moisture * julien.minet@uclouvain.be mapping at the field scale.

Characterization of tillage effects on the spatial variation of soil properties using ground-penetrating radar and electromagnetic induction

“…Among the SWC data sets available in this study, we chose the GPR data set, mainly because this sensor had a larger number of acquisition points and the largest support scale, resulting in the largest coverage rate among all the sensors used in this study (Jonard et al, 2011;Lambot et al, 2006;Minet et al, 2012). Therefore, the GPR could better capture the SWC variability at the plot scale.…”

In-Situ Measurement of Soil Permittivity at Various Depths for the Calibration and Validation of Low-Frequency SAR Soil Moisture Models by Using GPR

“…In low attenuation media, this method allows for high-resolution imaging of the shallow subsurface, where the imaging depth and resolution depends on the antenna frequencies. In the literature, GPR has been widely discussed as a non-destructive measurement technique for soil moisture data [13][14][15][16][17]. However, it is a highly intricate task to calculate the permittivity by using common-offset data alone, and even with the use of a priori knowledge, e.g., the reflector depth, the results are usually rather of a qualitative nature [18][19][20], and hence far from being suitable for serving as a "ground truth" for SAR data.…”

Targeted reflection-waveform inversion of experimental ground-penetrating radar data for quantification of oil spills under sea ice

“…They have become an area of active research in recent years for transmission data in borehole applications (Ernst et al, 2007;Klotzche et al, 2010Klotzche et al, , 2014 and for estimating near-surface soil properties from surface GPR data (Busch et al, 2012;Minet et al, 2012;Tran et al, 2012). In cryosphere applications, Schmid et al (2015) show significant potential to obtain snowpack properties from global, full-wavefield inversion of GPR reflection data in the frequency domain.…”