Abstract
A cokriging model using three variables is developed to estimate bare-surface soil moisture content based on multi-temporal synthetic-aperture radar (SAR) data. This model utilizes cross-semivariogram function to take into account spatially varied correlation among multiple variables. Here, five sentinel-1 SAR scenes were acquired on different dates using the interferometric wide-swath (IW) mode and a mean incidence angle of 39.02° to build the backscatter temporal-ratio in VV polarization. This algorithm is generally based on the assumption of contributions of soil moisture and surface roughness to the backscattering coefficient under the given radar configurations. In this study, soil moisture is the target variable, and the surface roughness and backscatter temporal-ratio in VV polarization are the auxiliary variables. A cross-semivariogram relationship is formulated among those three spatial variables; then ordinary cokriging is used, based on that cross-semivariogram formula, to estimate the spatial distribution of bare soil moisture content. The root mean square error (RMSE) of soil-moisture retrieval ranges from 2.62 to 2.66 vol%. The new empirical model described in this paper will provide new insights into the study of soil environments.
Résumé
Un modèle de cokrigeage utilisant 3 variables est développé afin d’évaluer le taux d’humidité d’un sol de surface nue sur la base des données multi-temporelles d’un radar à synthèse d’ouverture (RSO). Ce modèle utilise une fonction de semi-variogramme croisé pour prendre en considération la corrélation variée dans l’espace, entre plusieurs variables. Ici, cinq scènes RSO Sentinel 1 ont été acquises à différentes dates, utilisant le mode interférométrique à large bande et un angle d’incidence moyen de 39.02°, afin d’établir le temps relatif de rétrodiffusion en polarisation VV. Cet algorithme est généralement basé sur l’hypothèse d’une contribution de l’humidité du sol et de la rugosité des surfaces au coefficient de rétrodiffusion pour des configurations radar données. Dans cette étude, l’humidité du sol est la variable cible, et la rugosité de surface et le temps relatif de rétrodiffusion en polarisation VV sont des variables auxiliaires. Une relation de semi-variogramme croisé est formulée entre ces 3 variables spatiales; ensuite on utilise le cokrigeage classique, sur la base de cette formule, pour estimer la distribution spatiale du taux d’humidité d’un sol de surface nue. L’erreur quadratique moyenne (RMSE) de la récupération de l’humidité du sol est comprise entre 2.62 à 2.66% en volume. Le nouveau modèle empirique décrit dans le présent article fournira des nouveaux enseignements sur l’étude des environnements du sol.
Resumen
Se ha desarrollado un modelo de cokriging que utiliza tres variables para estimar el contenido de humedad del suelo en una superficie desnuda a partir de datos multitemporales del radar de apertura sintética (SAR). Este modelo utiliza una función de semivariograma cruzada para tener en cuenta la correlación espacialmente variada entre múltiples variables. Aquí se adquirieron cinco escenas de SAR sentinel-1 en diferentes fechas utilizando el modo interferométrico de barrido amplio (IW) y un ángulo de incidencia medio de 39.02° para construir la relación temporal de retrodispersión en la polarización VV. Este algoritmo se basa generalmente en el supuesto de que la humedad del suelo y la rugosidad de la superficie contribuyen al coeficiente de retrodispersión en las configuraciones dadas del radar. En este estudio, la humedad del suelo es la variable objetivo, y la rugosidad de la superficie y el coeficiente de retrodispersión temporal en la polarización VV son las variables auxiliares. Se formula una relación de semivariograma cruzado entre esas tres variables espaciales; luego se utiliza el cokriging ordinario, basado en esa fórmula de semivariograma cruzado, para estimar la distribución espacial del contenido de humedad del suelo sin vegetación. El error cuadrático medio de la raíz (RMSE) de la recuperación de la humedad del suelo oscila entre el 2.62% y el 2.66% del volumen. El nuevo modelo empírico que se describe en este documento proporcionará nuevas perspectivas para el estudio de los ambientes del suelo.
摘要
建立了使用三个变量的协同克里格模型,以基于多时段合成孔径雷达(SAR)数据估算裸露表面的土壤水分含量。该模型利用交叉半变异函数来考虑多个变量之间的空间变化相关性。在这里,使用干涉宽频(IW)模式和平均入射角为39.02°在不同的日期获取了5个哨兵1 号SAR场景,以建立VV极化的反向散射时间比。该算法通常基于在给定雷达设置下土壤水分和表面粗糙度对反向散射系数存在贡献的假设。在这项研究中,土壤水分是目标变量,VV极化的表面粗糙度和反向散射时间比是辅助变量。在这三个空间变量之间建立了交叉半变异函数关系。然后根据交叉半变异函数公式,使用普通协同克里格法估算裸露土壤水分的空间分布。土壤水分反演的均方根误差(RMSE)为2.62至2.66 vol%。本文描述的新的经验模型将为土壤环境研究提供新的参考。
Resumo
Um modelo de cokrigagem utilizando três variáveis é desenvolvido para estimar o teor de umidade do solo em superfície descoberta, com base em dados multitemporais de radar de abertura sintética (synthetic-aperture radar, SAR). Esse modelo utiliza uma função de semivariograma cruzado para levar em consideração a correlação espacialmente variada entre diversas variáveis. Aqui, cinco cenas de SAR sentinel-1 foram adquiridas em datas diferentes, utilizando o modo interferometria de ampla faixa (interferometric wide-swath, IW) e um ângulo de incidência médio de 39.02° para construir a razão temporal de retroespalhamento na polarização VV. Esse algoritmo é geralmente baseado na suposição de contribuições da umidade do solo e da rugosidade da superfície para o coeficiente de retroespalhamento sob as configurações de radar fornecidas. Neste estudo, a umidade do solo é a variável alvo e a rugosidade da superfície e a razão temporal de retroespalhamento na polarização VV são as variáveis auxiliares. Uma relação entre semivariograma é formulada entre essas três variáveis espaciais; então, a cokrigagem ordinária é aplicada, com base nessa fórmula do semivariograma cruzado, para estimar a distribuição espacial do teor de umidade do solo. A raiz do erro quadrático médio (REMQ) da recuperação da umidade do solo varia entre 2.62 e 2.66% em volume. O novo modelo empírico descrito neste artigo fornecerá novas ideias para estudos no ambiente do solo.
Similar content being viewed by others
References
Baghdadi N, Gherboudj I, Zribi M (2004) Semi-empirical calibration of the IEM backscattering model using radar images and moisture and roughness field measurements. Int J Remote Sens 25:3593–3623
Baghdadi N, Holah N, Zribi M (2006) Calibration of the integral equation model for Sar data in c-band and hh and vv polarizations. Int J Remote Sens 27:805–816
Baghdadi N, Chaaya JA, Zribi M (2011) Semiempirical calibration of the integral equation model for Sar data in c-band and cross polarization using radar images and field measurements. IEEE Geosci Remote S 8:14–18
Baghdadi N, Choker M, Zribi M, El Hajj M, Paloscia S, Verhoest N, Lievens H, Baup F, Mattia F (2016) A new empirical model for radar scattering from bare soil surfaces. Remote Sens. https://doi.org/10.3390/rs8110920
Balenzano A, Mattia F, Satalino G, Davidson MWJ (2011) Dense temporal series of C- and L-band SAR data for soil moisture retrieval over agricultural crops. IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing 4:439–450
Brocca L, Melone F, Moramarco T, Morbidelli R (2010) Spatial-temporal variability of soil moisture and its estimation across scales. Water Resour Res. https://doi.org/10.1029/2009WR008016
Chai T, Draxler RR (2014) Root mean square error (RMSE) or mean absolute error (MAE)? Arguments against avoiding RMSE in the literature. Geosci Model Dev 7:1247–1250
Chen KS, Wu TD, Tsang L, Li Q, Shi J, Fung AK (2003) Emission of rough surfaces calculated by the integral equation method with comparison to three-dimensional moment method simulations. IEEE T Geosci Remote 41:90–101
Choker M, Baghdadi N, Zribi M, Hajj EI, Paloscia M, Verhoest S, Lievens HNE, Mattia F (2017) Evaluation of the Oh, Dubois and IEM backscatter models using a large dataset of SAR data and experimental soil measurements. Water 9:38
Copernicus (2020) Copernicus Open Access Hub. https://scihub.copernicus.eu/dhus/#/home. Accessed May 2020
Dobson MC, Ulaby FT (1981) Microwave backscatter dependence on surface roughness, soil moisture, and soil texture: part III, soil tension. IEEE T Geosci Remote GE-19:51–61
Dobson MC, Ulaby FT (1985) Active microwave soil moisture research. IEEE T Geosci Remote GE-24:23–36
Dobson MC, Ulaby FT, Hallikainen MT, Elrayes MA (1985) Microwave dielectric behaviour of wet soil, part II: dielectric mixing models. IEEE T Geosci Remote 23:35–46
Dubois PC, Zyl JV, Engman T (1995) Measuring soil moisture with imaging radars. IEEE T Geosci Remote 33:915–926
Eldeiry AA, Garcia LA (2010) Comparison of ordinary kriging, regression kriging, and co-kriging techniques to estimate soil salinity using landsat images. J Irrig Drain Eng 136:355–364
Fung AK, Chen KS (1994) Microwave scattering and emission models and their applications. Artech House, London, pp 122–145
Fung AK, Li ZQ, Chen KS (1992) Backscattering from a randomly rough dielectric surface. IEEE T Geosci Remote 30:356–369
Jay MVH, Ronald PB (1998) Constructing and fitting models for cokriging and multivariable spatial prediction. J Stat Plan Infer 69:275–294
Juang KW, Lee DY (2000) Comparison of three nonparametric Kriging methods for delineating heavy-metal contaminated soils. J Environ Qual 29:197–205
Kang J, Jin R, Li X (2015) Regression kriging-based upscaling of soil moisture measurement from a wireless sensor network and multi-resource remote sensing information over heterogeneous cropland. IEEE Geosci Remote S 12:92–96
Kerr YH, Waldteufel P, Wigneron JP, Delwart S, Cabot F, Boutin J, Escorihuela MJ, Font J, Reul N, Gruhier C, Juglea SE, Drinkwater MR, Hahne A, Martin-Neira M, Mecklenburg S (2010) The SMOS mission: new tool for monitoring key elements of the global water cycle. P IEEE 98:666–687
Kornelsen KC, Coulibaly P (2017) Advances in soil moisture retrieval from synthetic aperture radar and hydrological applications. J Hydrol 476:460–489
Lawrence H, Demontoux F, Wigneron J, Paillou P, Wu T, Kerr YH (2011) Evaluation of a numerical modelling approach based on the finite-element method for calculating the rough surface scattering and emission of a soil layer. IEEE Geosci Remote S 8:953–957
Liu TL, Juang KW, Lee DY (2006) Interpolating soil properties using kriging combined with categorical information of soil maps. Soil Sci Soc Am J 70:1200–1209
Loew A, Mauser W (2006) A semiempirical surface backscattering model for bare soil surfaces based on a generalized power law spectrum approach. IEEE T Geosci Remote 44:1022–1035
Loew A, Ludwig R, Mauser W (2006) Derivation of surface soil moisture from ENVISAT ASAR wide swath and image mode data in agricultural areas. IEEE T Geosci Remote 44:889–899
Mattia F, Satalino G, Dente L, Pasquariello G (2006) Using a priori information to improve soil moisture retrieval from ENVISAT ASAR AP data in semiarid regions. IEEE T Geosci Remote 44:900–912
Matheron G (1963) Principles of geostatistics. Econ Geol 58:1246–1266
Mishra U, Lal R, Slater B (2009) Predicting soil organic carbon stock using profile depth distribution functions and ordinary kriging. Soil Sci Soc Am J 73:614–621
Mirsoleimani HR, Sahebi NMR, Baghdadi N, Hajj ME (2019) Bare soil surface moisture retrieval from sentinel-1 SAR data based on the calibrated IEM and Dubois models using neural networks. Sensors. https://doi.org/10.3390/s19143209
Mohanty BP, Cosh MH, Lakshmi V, Montzka C (2017) Soil moisture remote sensing: state-of-the-science. Vadose Zone J. https://doi.org/10.2136/vzj2016.10.0105
Narvekar PS, Entekhabi D, Kim SB, Njoku EG (2015) Soil moisture retrieval using l-band radar observations. IEEE T Geosci Remote 53:3492–3506
Oh Y (2004) Quantitative retrieval of soil moisture content and surface roughness from multi-polarized radar observations of bare soil surfaces. IEEE T Geosci Remote 42:596–601
Oh Y, Sarabandi K, Ulaby FT (1992) An empirical model and an inversion technique for radar scattering from bare soil surfaces. IEEE T Geosci Remote 30:370–381
Oh Y, Sarab K, Ulaby FT (2002) Semi-empirical model of the ensemble-averaged differential Mueller matrix for microwave backscattering from bare soil surfaces. IEEE T Geosci Remote 40:1348–1355
Oliver MA, Webster R (2014) A tutorial guide to geostatistics: computing and modelling variograms and kriging. Catena 113:56–69
Onier C, Chanzy A, Chambarel A, Rouveure R, Chanet M, Bolvin H (2011) Impact of soil structure on microwave volume scattering evaluated by a two-dimensional numerical model. IEEE T Geosci Remote 49:415–425
Panciera R, Tanase MA, Lowell K, Walker JP (2014) Evaluation of IEM, Dubois, and Oh radar backscatter models using airborne L-band SAR. IEEE T Geosci Remote 52:4966–4979
Paloscia S, Pettinato S, Santi E, Notarnicola C, Pasolli L, Reppucci A (2013) Soil moisture mapping using Sentinel-1 images: algorithm and preliminary validation. Remote Sens Environ 134:234–248
Peng J, Loew A, Merlin O, Verhoest NEC (2017) A review of spatial downscaling of satellite remotely sensed soil moisture. Rev Geophys. https://doi.org/10.1002/2016RG00543
Rabus B, When H, Nolan M (2010) The importance of soil moisture and soil structure for InSAR phase and backscatter, as determined by FDTD modelling. IEEE T Geosci Remote 48:2421–2429
Schmugge TJ, Kustas WP, Ritchie JC, Jackson TJ, Rango A (2002) Remote sensing in hydrology. Adv Water Resour 25:1367–1385
Shi J, Wang J, Hsu AY (1995) Estimation of bare soil moisture and surface roughness parameters using l-band Sar image data. IGARSS’95. https://doi.org/10.1109/IGARSS.1995.520322
Shi JC, Wang J, Hsu AY, O’Neill PE, Engman ET (1997) Estimation of bare surface soil moisture and surface roughness parameter using L-band SAR image data. IEEE T Geosci Remote 35:1254–1266
Smith JL, Halvorson JJ, Papendick RI (1993) Using multiple-variable indicator kriging for evaluating soil quality. Soil Sci Soc Am J 57:743–749
Snepvangers JJJC, Heuvelink GBM, Huisman JA (2003) Soil water content interpolation using spatio-temporal kriging with external drift. GEODERMA 112:253–271
Ulaby FT, Batlivala PP, Dobson MC (1978) Microwave backscatter dependence on surface roughness, soil moisture, and soil texture: part I, bare soil. IEEE T Geosci Remote GE-16:286–295
Ulaby FT, Moore RK, Fung AK (1982) Microwave remote sensing active and passive, vol II: radar remote sensing and surface scattering and emission theory. Artech House, Norwood, MA
Vauclin M, Vieira SR, Vachaud G, Nielsen DR (1983) The use of cokriging with limited field soil observations. Soil Sci Soc Am J 47:175–184
Wagner W, Pathe C, Doubkova M, Sabel D, Bartsch A, Hasenauer S, Blöschl G, Scipal K, Martínez-Fernández J, Löw A (2008) Temporal stability of soil moisture and radar backscatter observed by the advanced synthetic aperture radars (ASAR). Sensors 8:1174–1197
Warnick KF, Chew WC (2001) Numerical simulation methods for rough surface scattering. Waves Random Media 11:R1–R30
Western AW, Grayson RB, Blöschl G (2002) Scaling of soil moisture: a hydrologic perspective. Annu Rev Earth PL SC 30:149–180
Wigneron JP, Calvet JC, Pellarin T, Van de Griend AA, Berger M, Ferrazzoli P (2003) Retrieving near-surface soil moisture from microwave radiometric observations: current status and future plans. Remote Sens Environ 85:489–506
Withers CS, Nadarajah S (2014) Simple alternatives for Box–Cox transformations. Metrika 77:297–315
Wu TD, Chen KS, Shi J, Fung AK (2001) A transition model for the reflection coefficient in surface scattering. IEEE T Geosci Remote 39:2040–2050
Xing CJ, Chen NC, Zhang X, Gong JY (2017) A machine learning based reconstruction method for satellite remote sensing of soil moisture images with in situ observations. Remote Sens. https://doi.org/10.3390/rs9050484
Yan G, Zhou S, Zhou LQ, Xi J, Tian YF, Teng HF (2013) Integrating remote sensing and proximal sensors for the detection of soil moisture and salinity variability in coastal areas. J Integr Agr 12:723–731
Yang Y, Wu JP, Christakos G (2015) Prediction of soil heavy metal distribution using spatiotemporal kriging with trend model. Ecol Indic 56:125–133
Yao T (1999) Nonparametric cross-covariance modeling as exemplified by soil heavy metal concentrations from the Swiss Jura. Geoderma 88:38
Yates SR, Warrick AW (1987) Estimating soil water content using cokriging. Soil Sci Soc Am J 51:23–30
Zhang JL, Li X, Yang R, Liu Q, Zhao L, Dou B (2017) An extended kriging method to interpolate near-surface soil moisture data measured by wireless sensor networks. Sensor. https://doi.org/10.3390/s17061390
Zhang X, Tang XM, Gao XM, Zhao H (2018) Multitemporal soil moisture retrieval over bare agricultural area by means of alpha model with multisensory SAR data. Adv Meteorol. https://doi.org/10.1155/2018/7914581
Zhao W, Li A, Jin H, Zhang Z, Bian J, Yin G (2017) Performance evaluation of the triangle-based empirical soil moisture relationship models based on Landsat-5 TM data and in situ measurements. IEEE T Geosci Remote 55:2632–2645
Zhao W, Sánchez N, Lu H, Li A (2018) A spatial downscaling approach for the SMAP passive surface soil moisture product using random forest regression. J Hydrol 563:1009–1024
Zhu B, Song X, Leng P (2016) A novel simplified algorithm for bare surface soil moisture retrieval using l-band radiometer. ISPRS Int J Geo-Inf 5:143–158
Zribi M, Dechambre M (2003) A new empirical model to retrieve soil moisture and roughness from c-band radar data. Remote Sens Environ 84:42–52
Zribi M, Baghdadi N, Holah N, Fafin O (2005) New methodology for soil surface moisture estimation and its application to ENVISAT-ASAR multi-incidence data inversion. Rem Sens Environ 96:485–496
Acknowledgements
Thanks go to Dr. Gareth Fabbro and Dr. Xuanlong Ma for reviewing the English text.
Funding
This research was jointly supported by the Research Initiation Fund for Teacher Development from Chengdu University of Technology (10912-2019KYQD07430), the research projects from the “National Natural Science Foundation of China” (41672325 and 1212011085468), the research project from “National Key R&D Program of China” (2017YFC0601505), and a research project from the “The State Key Research Project in 13th Five-Year” (51569018).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Zeng, L., Shi, Q., Guo, K. et al. A three-variables cokriging method to estimate bare-surface soil moisture using multi-temporal, VV-polarization synthetic-aperture radar data. Hydrogeol J 28, 2129–2139 (2020). https://doi.org/10.1007/s10040-020-02177-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s10040-020-02177-z