Validation of SMOS Data Over Agricultural and Boreal Forest Areas in Canada

This study was conducted as part of the Soil Moisture and Ocean Salinity (SMOS) calibration and validation activities over agricultural and boreal forest sites located in Saskatchewan, Canada. For each site covering 33 km × 71 km (i.e., about two SMOS pixels), we examined the SMOS brightness temperature (L1c) and soil moisture (L2) products from May 1 to September 30, 2010. The consistency of these data with respect to theory and to the temporal variation of surface characteristics was first discussed at both sites. Then, the SMOS L1c (prototype 346) and L2 (prototypes 305-309) products were evaluated using the Canadian Experiment for Soil Moisture in 2010 (CanEx-SM10) ground measurements and L-band passive microwave airborne measurements, in addition to AMSR-E soil moisture estimates and simulations from the zeroth order τ- ω radiative transfer model. For both study sites, the model underestimated SMOS brightness temperatures in V polarization, whereas an overestimation was observed in H polarization. The data sets showed that both the SMOS and AMSR-E soil moisture values were underestimated compared with ground measurements collected during CanEx-SM10 but less so for the AMSR-E estimates. The SMOS soil moisture product was underestimated with a RMSE varying from 0.15 to 0.18 m3/ m3. Furthermore, the overall results showed that errors in the soil moisture estimates increased with the absolute value of soil moisture.

[1]  B. Choudhury,et al.  Remote sensing of soil moisture content over bare field at 1.4 GHz frequency , 1981 .

[2]  Y. Kerr.  Soil moisture from space: Where are we? , 2007 .

[3]  Sidharth Misra,et al.  Airborne L-Band Radio Frequency Interference Observations From the SMAPVEX08 Campaign and Associated Flights , 2011, IEEE Transactions on Geoscience and Remote Sensing.

[4]  Yann Kerr,et al.  Results of combining L- and C-band passive microwave airborne data over the Sahelian area , 2000, IEEE Trans. Geosci. Remote. Sens..

[5]  Thomas J. Jackson,et al.  Soil moisture mapping and AMSR-E validation using the PSR in SMEX02 , 2006 .

[6]  Yann Kerr,et al.  A simple parameterization of the L-band microwave emission from rough agricultural soils , 2001, IEEE Trans. Geosci. Remote. Sens..

[7]  Y. Kerr,et al.  L-band Microwave Emission of the Biosphere (L-MEB) Model: Description and calibration against experimental data sets over crop fields , 2007 .

[8]  T. Mo,et al.  A Parameterization of the Effect of Surface Roughness on Microwave Emission , 1987, IEEE Transactions on Geoscience and Remote Sensing.

[9]  Thomas J. Jackson,et al.  A First-Order Radiative Transfer Model for Microwave Radiometry of Forest Canopies at L-Band , 2011, IEEE Transactions on Geoscience and Remote Sensing.

[10]  C. Utku,et al.  ESTAR and model brightness temperatures over forests: effects of soil moisture , 2001, IGARSS 2001. Scanning the Present and Resolving the Future. Proceedings. IEEE 2001 International Geoscience and Remote Sensing Symposium (Cat. No.01CH37217).

[11]  A. Berg,et al.  Streamflow predictability in the Saskatchewan/Nelson River basin given macroscale estimates of the initial soil moisture status , 2006 .

[12]  Emanuele Santi,et al.  Modeling the Multifrequency Emission of Broadleaf Forests and Their Components , 2010, IEEE Transactions on Geoscience and Remote Sensing.

[13]  Jean-Pierre Wigneron,et al.  Synergy of SMOS Microwave Radiometer and Optical Sensors to Retrieve Soil Moisture at Global Scale , 2008, IEEE Transactions on Geoscience and Remote Sensing.

[14]  Eric F. Wood,et al.  Evaluation of Special Sensor Microwave/Imager Satellite Data for Regional Soil Moisture Estimation over the Red River Basin , 1997 .

[15]  Jean-Pierre Wigneron,et al.  Monitoring forests from L-band microwave observations , 2003, IGARSS 2003. 2003 IEEE International Geoscience and Remote Sensing Symposium. Proceedings (IEEE Cat. No.03CH37477).

[16]  T. Schmugge,et al.  Vegetation effects on the microwave emission of soils , 1991 .

[17]  Yann Kerr,et al.  Passive microwave remote sensing of land-atmosphere interactions , 1995 .

[18]  P. Dirmeyer,et al.  Evaluation of AMSR-E soil moisture results using the in-situ data over the Little River Experimental Watershed, Georgia , 2008 .

[19]  R. Earnshaw,et al.  Digital Media , 1996, Encyclopedia of Social Network Analysis and Mining. 2nd Ed..

[20]  Yann Kerr,et al.  Soil moisture retrieval from space: the Soil Moisture and Ocean Salinity (SMOS) mission , 2001, IEEE Trans. Geosci. Remote. Sens..

[21]  Imen Gherboudj,et al.  Soil moisture retrieval over agricultural fields from multi-polarized and multi-angular RADARSAT-2 SAR data , 2011 .

[22]  B. Ludwig,et al.  Hydrological structure and erosion damage caused by concentrated flow in cultivated catchments , 1995 .

[23]  Jeffrey P. Walker,et al.  Soil moisture retrievals at L-band using a two-step inversion approach (COSMOS/NAFE'05 Experiment) , 2009 .

[24]  Rocco Panciera,et al.  AMSR-E Soil Moisture Validation Efforts in the Australian Arid Zone , 2003 .

[25]  B. Choudhury,et al.  Effect of surface roughness on the microwave emission from soils , 1979 .

[26]  Mahta Moghaddam,et al.  Estimation of crown and stem water content and biomass of boreal forest using polarimetric SAR imagery , 2000, IEEE Trans. Geosci. Remote. Sens..

[27]  Heather McNairn,et al.  Evaluation of soil moisture derived from passive microwave remote sensing over agricultural sites in Canada using ground-based soil moisture monitoring networks , 2010 .

[28]  A. Elshorbagy,et al.  Utilizing North American Regional Reanalysis for modeling soil moisture and evapotranspiration in reconstructed watersheds , 2011 .

[29]  Thomas J. Jackson,et al.  L-Band Radar Estimation of Forest Attenuation for Active/Passive Soil Moisture Inversion , 2009, IEEE Transactions on Geoscience and Remote Sensing.

[30]  Keiji Imaoka,et al.  AMSR/AMSR-E level 2 and 3 algorithm developments and data validation plans of NASDA , 2003, IEEE Trans. Geosci. Remote. Sens..

[31]  J. Wigneron,et al.  Retrieving near-surface soil moisture from microwave radiometric observations : current status and future plans , 2003 .

[32]  Thomas J. Schmugge,et al.  Applications of passive microwave observations of surface soil moisture , 1996, IGARSS '96. 1996 International Geoscience and Remote Sensing Symposium.

[33]  Li Li,et al.  Retrieval of land surface parameters using passive microwave measurements at 6-18 GHz , 1999, IEEE Trans. Geosci. Remote. Sens..

[34]  Venkat Lakshmi,et al.  Remote Sensing of Soil Moisture , 2013 .

[35]  Thomas R. H. Holmes,et al.  An evaluation of AMSR–E derived soil moisture over Australia , 2009 .

[36]  F. Ulaby,et al.  Microwave Dielectric Behavior of Wet Soil-Part II: Dielectric Mixing Models , 1985, IEEE Transactions on Geoscience and Remote Sensing.

[37]  M. Mccabe,et al.  Evaluation of AMSR-E-Derived Soil Moisture Retrievals Using Ground-Based and PSR Airborne Data during SMEX02 , 2005 .

[38]  James R. Wang,et al.  Multifrequency Measurements of the Effects of Soil Moisture, Soil Texture, And Surface Roughness , 1983, IEEE Transactions on Geoscience and Remote Sensing.

[39]  Lifeng Luo,et al.  Contribution of land surface initialization to subseasonal forecast skill: First results from a multi‐model experiment , 2010 .

[40]  Yann Kerr,et al.  L-MEB: A simple model at L-band for the continental areas - Application to the simulation of a half-degree resolution and global scale data set. , 2006 .

[41]  Thomas J. Jackson,et al.  Soil moisture mapping at regional scales using microwave radiometry: the Southern Great Plains Hydrology Experiment , 1999, IEEE Trans. Geosci. Remote. Sens..

[42]  Melissa Bukovsky,et al.  A Brief Evaluation of Precipitation from the North American Regional Reanalysis , 2007 .

[43]  Rong Fu,et al.  A Practical Method for Retrieving Land Surface Temperature From AMSR-E Over the Amazon Forest , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[44]  Thomas J. Jackson,et al.  Soil moisture retrieval from AMSR-E , 2003, IEEE Trans. Geosci. Remote. Sens..

[45]  Emanuele Santi,et al.  A multifrequency algorithm for the retrieval of soil moisture on a large scale using microwave data from SMMR and SSM/I satellites , 2001, IEEE Trans. Geosci. Remote. Sens..

[46]  Yann Kerr,et al.  A Simple Model of the Bare Soil Microwave Emission at L-Band , 2007, IEEE Transactions on Geoscience and Remote Sensing.

[47]  T. Jackson,et al.  Using TRMM/TMI to Retrieve Surface Soil Moisture over the Southern United States from 1998 to 2002 , 2006 .

[48]  A. Fung,et al.  Microwave Remote Sensing Active and Passive-Volume III: From Theory to Applications , 1986 .

[49]  Emanuele Santi,et al.  Soil Moisture Estimates From AMSR-E Brightness Temperatures by Using a Dual-Frequency Algorithm , 2006, IEEE Transactions on Geoscience and Remote Sensing.

[50]  E. Njoku,et al.  Vegetation and surface roughness effects on AMSR-E land observations , 2006 .

[51]  Jean-Pierre Wigneron,et al.  Simulating L-band emission of forests in view of future satellite applications , 2002, IEEE Trans. Geosci. Remote. Sens..

[52]  Adriano Camps,et al.  Polarimetric formulation of the visibility function equation including cross-polar antenna patterns , 2005, IEEE Geoscience and Remote Sensing Letters.

[53]  E. Njoku,et al.  Passive microwave remote sensing of soil moisture , 1996 .