A farm’s soil moisture and soil electrical conductivity (EC)readings are extremely valuable for a farmer. They can help her reduce water use and improve productivity. However, the high cost of commercial soil moisture sensors and the inaccuracy of sub-1000 dollar EC sensors have limited their adoption. In this paper, we present the design and implementation of a system, called Strobe, that senses soil moisture and soil EC using RF propagation in existing Wi-Fi bands. Strobe overcomes the key challenge of limited bandwidth availability in the 2.4 GHz unlicensed spectrum using a novel multi-antenna technique. It maps the propagation time and amplitude of Wi-Fi signals received by different antennas to the soil permittivity and EC, which in turn depend on soil moisture and salinity. Our experiments with USRP, WARP, and commodity Wi-Fi cards show that Strobe can accurately estimate soil moisture and EC using Wi-Fi, thereby showing the potential of a future in which a farmer can sense soil in their farm without investing 1000s of dollars in soil sensing equipments.
Citation Jian Ding and Ranveer Chandra 2019 Towards Low Cost Soil Sensing Using WiFi. In The 25th Annual International Conference on Mobile Computing and Networking (MobiCom’19), October 21-25, 2019, Los Cabos, Mexico. ACM, New York, NY, USA, 16pages. https://doi.org/10.1145/3300061.3345440
Date October 2019