volume | PIER Journals

Abstract

This paper reports a neural-network-based methodology to estimate the amount of moisture content in soil at L, S and C frequency bands. A multilayered artificial neural network, using the Levenberg-Marquardt algorithm, is used as the ANN model. The input training data comprise the measured values of dielectric constant of soil in the dry and moist states. Dielectric constant is measured using microwave free-space transmission technique. Measurement has been performed using Vector Network Analyzer (VNA), microstrip patch antenna and soil sample holder. One great advantage with this method is that there is no need to test the pH value of the soil sample, and hence all the associated pre-processing steps, such as drying, pulverizing, can be avoided.

1. CMG Garden Notes 211 Colorado State University Extension, 2011.

2. Wastelands Atlas of India, Land Use Division, Land Resources Group, RS & GIS Applications Area, National Remote Sensing Centre, Indian Space Research Organisation, Hyderabad, 2010.

3. Freedman, G., "The future of microwave heating equipment in the food industries," Microwave Power, Vol. 7, 1973.

4. Fox, M. J., Handbook of Microwave Measurements, Polytechnic Press Institute, 1963.

5. Nelson, S. O., "Dielectric properties measuring techniques and applications," American Society of Agricultural Engineers, Paper No. 983067. St. Joseph, MI, 1998.

6. Rajesh Mohan, R., B. Paul, S. Mridula, and P. Mohanan, "Measurement of soil moisture content at microwave frequencies," International Conference on Information and Communication Technologies (ICICT 2014), Elsevier Procedia Computer Science, Vol. 46, 1238-1245, 2015.
doi:10.1007/1-4020-3288-9

7. Behari, J., Microwave Dielectric Behaviour of Wet Soils, Anamaya Publishers, 2005.

8. Venkatesh, M. S. and G. S. V. Raghavan, "An overview of dielectric properties measuring techniques," Canadian Biosystems Engineering, Vol. 47, 2005.
doi:10.1029/WR016i003p00574

9. Topp, G. C., J. L. Davis, and A. P. Annan, "Electromagnetic determination of soil water content and electrical conductivity measurement using time domain reflectometry," Water Resources Research, Vol. 16, 574-582, 1980.

10. Trabelsi, S. and S. O. Nelson, Free-space Measurement of Dielectric Properties of Cereal Grain and Oilseed at Microwave Frequencies, 589-600, Institute of Physics Publishing, 2003.

11. Analysis report Form ST-4, District Soil Testing Laboratory, Ernakulam and Palakkad, Kerala, South India, 2014.
doi:10.1002/mop.21230

12. Ouchar, A., R. Aksas, and H. Baudrand, "Artificial neural network for computing the resonant frequency of circular patch antennas," Microwave and Optical Technology Letters, Vol. 47, No. 6, 564-566, 2005.
doi:10.1109/MAP.2011.5773614

13. Hasan, A. and A. F. Peterson, "Measurement of complex permittivity using artificial neural networks," IEEE Antennas and Propagation Magazine, Vol. 53, No. 1, 2011.

Dr. Raman Menon Rajesh Mohan

Professor Shanta Mridula

Professor Pezholil Mohanan