volume | PIER Journals

Abstract

A multilayer soil model for retrieving soil moisture content using the Integral Equation Method (IEM) is investigated in this paper. The total reflection coefficients of the natural soil are obtained using the multilayer model, and volumetric scattering is approximated by the internal reflections between layers. The surface reflection terms in IEM model are replaced by the total reflection coefficients from the multi-layer soil surface in retrieving the soil moisture content. The original IEM model includes only the surface scattering of the natural bare soil, while the multilayer soil - IEM model (MS-IEM) includes both the surface scattering and the volumetric scattering within the soil. Both the MS-IEM model and the original IEM model are compared in soil moisture retrieval using the experimental Synthetic Aperture Radar (SAR) backscattering coefficient data in the literature. It is noted that the mean square error between the measurement data and the values estimated by the modified IEM model is about 7.7%, while that between the measured and the estimated by the original IEM model is about 12%. The accuracy of estimating soil moisture by the IEM model is improved by 4.3%. In addition, the regression analysis between the measured and model-predicted soil moistures has been done.

1. Verhoest, N. E. C., B. De Baets, and H. Vernieuwe, "A Takagi-Sugeno fuzzy rule-based model for soil moisture retrieval from SAR under soil roughness uncertainty," IEEE Transactions on Geoscience and Remote Sensing, Vol. 45, No. 2, 1351-1360, 2007.
doi:10.1109/TGRS.2007.894930 Google Scholar

2. Kuo, C.-H. and M. Mahta, "Electromagnetic scattering from multilayer rough surfaces with arbitrary dielectric profiles for remote sensing of subsurface soil moisture," IEEE Transactions on Geoscience and Remote Sensing, Vol. 45, No. 2, 349-366, 2007.
doi:10.1109/TGRS.2006.887164 Google Scholar

3. Oh, Y., "Quantitative retrieval of soil moisture content and surface roughness from multipolarized radar observations of bare soil surfaces," IEEE Transactions on Geoscience and Remote Sensing, Vol. 42, No. 3, 596-601, 2004.
doi:10.1109/TGRS.2003.821065 Google Scholar

4. Zribi, M. and M. Dechambre, "A new empirical model to retrieve soil moisture and roughness from C-band radar data," Remote Sensing of Environment, Vol. 84, No. 1, 42-52, 2003.
doi:10.1016/S0034-4257(02)00069-X Google Scholar

5. Dubois, P. C., J. V. Zyl, and T. Engman, "Measuring soil moisture with imaging radars," IEEE Transactions on Geoscience and Remote Sensing, Vol. 33, No. 4, 915-926, 1995.
doi:10.1109/36.406677 Google Scholar

6. Oh, Y., K. Sarabandi, and F. T. Ulaby, "An empirical model and inversion technique for radar scattering from bare soil surface," IEEE Transactions on Geoscience and Remote Sensing, Vol. 30, No. 2, 370-381, 1992.
doi:10.1109/36.134086 Google Scholar

7. Ulaby, F. T., R. K. Moore, and A. K. Fung, Microwave Remote Sensing: Active and Passive, Vol. 2, Addison-Wesley, 1982.

8. Fung, A. K., Z. Li, and K. S. Chen, "Backscattering from a randomly rough dielectric surface," IEEE Transactions on Geoscience and Remote Sensing, Vol. 30, No. 2, 356-369, 1992.
doi:10.1109/36.134085 Google Scholar

9. Fung, A. K., Microwave Scattering and Emission Models and Their Applications, Artech House, 1994.

10. Ulaby, F. T., R. K. Moore, and A. K. Fung, Microwave Remote Sensing, Active and Passive, Vol. 1, Addison-Wesley, 1981.

11. Tsang, L., K. H. Ding, and B. Wen, "Dense media radiative transfer theory for dense discrete random media with particles of multiple sizes and permittivities," Progress In Electromagnetics Research, Vol. 6, 181-230, 1992. Google Scholar

12. Topp, G. C. and J. L. Davis, "Measurements of soil water content using time domain reflectometry: A field evaluation," Soil Sci. Am. J., Vol. 49, 19-24, 1985.
doi:10.2136/sssaj1985.03615995004900010003x Google Scholar

13. Topp, G. C., J. L. Davis, and A. P. Annan, "Electromagnetic determination of soil water content: Measurement in coaxial transmission lines," Water Resour. Res., Vol. 16, 574-582, 1980.
doi:10.1029/WR016i003p00574 Google Scholar

14. Oh, Y., K. Sarabandi, and F. T. Ulaby, "Semi-empirical model of the ensemble-averaged differential mueller matrix for microwave backscattering from bare soil surfaces," IEEE Transactions on Geoscience and Remote Sensing, Vol. 40, No. 6, 1348-1355, 2002.
doi:10.1109/TGRS.2002.800232 Google Scholar

15. Sano, E. E., M. S. Moran, A. R. Huete, and T. Miura, "C- and multiangle Ku-band synthetic aperture radar data for bare soil moisture estimation in agricultural areas," Remote Sens. of Environ., Vol. 64, 77-90, 1998.
doi:10.1016/S0034-4257(97)00170-3 Google Scholar

16. Bolten, J. D., V. Lakshmi, and E. G. Njoku, "Soil moisture retrieval using the passive/active L- and S-band radar/radiometer," IEEE Transactions on Geoscience and Remote Sensing, Vol. 41, 2792-2801, 2003.
doi:10.1109/TGRS.2003.815401 Google Scholar

17. Neusch, T. and M. Sties, "Application of the Dubois-model using experimental synthetic aperture radar data for the determination of soil moisture and surface roughness," ISPRS Journal of Photogrammetry & Remote Sensing, Vol. 54, 273-278, 1999.
doi:10.1016/S0924-2716(99)00019-2 Google Scholar

18. Oh, Y., "Robust inversion technique for retrieving soil moisture from multi-polarised backscatter of bare surface," Electronics Letters, Vol. 42, No. 7, 414-415, 2006.
doi:10.1049/el:20064083 Google Scholar

19. Wang, Y.-Q. and Y.-Q. Jin, "A genetic algorithm to simultaneously retrieve land surface roughness and soil moisture," Journal of Remote Sensing, Vol. 4, No. 2, 90-94, 2000. Google Scholar

20. Yan, S. H., X. B. Wu, and Z. Z. Chen, "Remote sensing with TDMF radar: some preliminary results," Progress In Electromagnetics Research Letters, Vol. 14, 79-90, 2010.
doi:10.2528/PIERL10022405 Google Scholar

21. Song, K., X. Zhou, and Y. Fan, "Empirically adopted IEM for retrieval of soil moisture from radar backscattering coefficients," IEEE Transactions on Geoscience and Remote Sensing, Vol. 47, 1662-1672, 2009.
doi:10.1109/TGRS.2008.2009061 Google Scholar

22. Prasad, R., R. Kumar, and D. Singh, "A radial basis function approach to retrieve soil moistrure and crop variables from X-band scatterometer ovservations," Progress In Electromagnetics Research B, Vol. 12, 201-217, 2009.
doi:10.2528/PIERB08120703 Google Scholar

23. Singh, D., V. Srivastava, B. Pandey, and D. Bhimsaria, "Application of neural network with error correlation and time evolution for retrieval of soil moisture and other vegetation variables," Progress In Electromagnetics Research B, Vol. 15, 245-265, 2009.
doi:10.2528/PIERB09043003 Google Scholar

24. Liang, D., P. Xu, L. Tsang, Z. Gui, and K.-S. Chen, "Electromagnetic scattering by rough surfaces with large heights and slopes with applications to microwave remote sensing of rough surface over layered media," Progress In Electromagnetics Research, Vol. 95, 199-218, 2009.
doi:10.2528/PIER09071413 Google Scholar

25. Shi, J., J. Wang, A. Y. Hsu, P. E. O'Neill, and E. T. Engman, "Estimation of bare surface soil moisture and surface roughness parameter using L-band SAR image data," IEEE Transactions on Geoscience and Remote Sensing, Vol. 35, 1254-1266, 1997. Google Scholar

26. Chen, M. F. and A. K. Fung, "A numerical study of the regions of validity of the Kirchhoff and small perturbation rough surface scattering models," Radio Science, Vol. 23, 163-170, 1988.
doi:10.1029/RS023i002p00163 Google Scholar

27. Walker, J. P., P. A. Troch, M. Mancini, G. R. Willgoose, and J. D. Kalma, "Profile soil moisture estimation using the modified IEM," IEEE International Geoscience and Remote Sensing Symposium, IGARSS, Vol. 3, 1263-1265, 1997. Google Scholar

28. Fung, A. K., M. S. Dawson, K. S. Chen, A. Y. Hsu, E. T. Engman, P. O. O'Neill, and J.Wang, "A modified IEM model for: scattering from soil surfaces with application to soil moisture sensing," IEEE International Geoscience and Remote Sensing Symposium, IGARSS, Vol. 2, 1297-1299, 1996. Google Scholar

29. Cuiñas, I., D. Martínez, M. G. Sánchez, and A. V. Alejos, "Modelling and measuring reflection due to flat dielectric surfaces at 5.8 GHz," IEEE Transactions on Antennas and Propagation, Vol. 55, 1139-1141, 2007. Google Scholar

30. Burnside, W. D. and K. W. Burgener, "High frequency scattering by a thin lossless dielectric slab," IEEE Transactions on Antennas and Propagation, Vol. 31, 104-110, 1983.
doi:10.1109/TAP.1983.1143019 Google Scholar

Dr. Kaijun Song

Dr. Xiaobing Zhou

Prof. Yong Fan