Comparison of radio frequency path loss models in soil for wirelessunderground sensor networks

[摘要] Recent developments in electronics and wireless communication systems have enabled the expansion of low cost and low power Wireless Underground Sensor Networks.In this research existing models such as the Modified-Friis and Crim-Fresnel for RF transmission were critically reviewed and the results from these models compared with measurements obtained from laboratory and field trials. This provides a further understanding of the dielectric properties of soil affecting the attenuation of EM signals and their relationship with soil type and condition (i.e. water content, clay content and density). A new methodology has been developed to accurately measure the EM signal attenuation for a range of soil compositions. From a comparison of the results obtained during this research, it is concluded that the permittivity values extracted from the TDR can be used as an input parameter to the Modified- Friis model. In addition, results from this study showed that the Modified-Friis model based on TDR values provided a better estimation of RF attenuation compared to the conventional Modified-Friis model. This can greatly simplify the process of estimation of RF attenuation in soil by removing the sampling and laboratory analysis (i.e. particle size distribution tests) steps which are required for the conventional mixing models.

[发布机构] University:University of Birmingham;Department:School of Engineering, Department of Mechanical Engineering

[关键词] Q Science;QC Physics