Soil Scouts: Description and performance of single hop wireless underground sensor nodes

Abstract Soil Scouts are palm-size wireless underground sensor nodes for monitoring of agriculture soil parameters. The system design is guided by two main criterions: (i) the data packets from underground sensor nodes must be received from up to 1 km away and (ii) the maintenance free underground sensor nodes must be capable of operating for a decade. System solutions are discussed compared to technical restraints and topology issues. Underground sensor nodes communicating with each other would require an excessive density of devices to overcome the range requirement and multi-hop routing would make the energy conservation requirement hard to achieve. This is why the single-hop approach is chosen. 11 Soil Scout prototypes are installed in a heavy clay soil, where up to 236 m distances and −110 dB calculated path losses are overcome with a directive 60° receiving antenna. A reference Soil Scout is installed in a sandy soil, where the 300 m distance is managed uninterruptedly with an omnidirectional receiving antenna. Battery voltage decline for the nodes as well as for previous Soil Scout designs are presented and observed to decline for 18 months and then obtain a sustaining annual temperature dependent fluctuation.

[1]  J. Tiusanen.  Wireless Soil Scout prototype radio signal reception compared to the attenuation model , 2009, Precision Agriculture.

[2]  Ian F. Akyildiz,et al.  Dynamic Connectivity in Wireless Underground Sensor Networks , 2011, IEEE Transactions on Wireless Communications.

[3]  J. Donner.  The Quaternary History of Scandinavia , 1995 .

[4]  Zhi Sun,et al.  Magnetic Induction Communications for Wireless Underground Sensor Networks , 2010, IEEE Transactions on Antennas and Propagation.

[5]  J. Tiusanen,et al.  Wideband Antenna for Underground Soil Scout Transmission , 2006, IEEE Antennas and Wireless Propagation Letters.

[6]  H. Vereecken,et al.  Evaluation of a low-cost soil water content sensor for wireless network applications , 2007 .

[7]  Mario Di Francesco,et al.  Energy conservation in wireless sensor networks: A survey , 2009, Ad Hoc Networks.

[8]  Ian F. Akyildiz,et al.  Wireless underground sensor networks: Research challenges , 2006, Ad Hoc Networks.

[9]  Ian F. Akyildiz,et al.  Signal propagation techniques for wireless underground communication networks , 2009, Phys. Commun..

[10]  Paul J.M. Havinga,et al.  A new wireless underground network system for continuous monitoring of soil water contents , 2009 .

[11]  Johannes Tiusanen.  Validation and results of the Soil Scout radio signal attenuation model , 2007 .

[12]  Calvin D. Perry,et al.  A real-time wireless smart sensor array for scheduling irrigation , 2008 .

[13]  Fawwaz T. Ulaby,et al.  Corrections to "Dielectric Properties of Soils in the 0.3-1.3-GHz Range" , 1995, IEEE Trans. Geosci. Remote. Sens..

[14]  Willem Bouten,et al.  Frequency domain analysis of time domain reflectometry waveforms: 2. A four‐component complex dielectric mixing model for soils , 1994 .

[15]  Johannes Tiusanen,et al.  Attenuation of a Soil Scout Radio Signal , 2005 .

[16]  Heye Bogena,et al.  Hybrid Wireless Underground Sensor Networks: Quantification of Signal Attenuation in Soil , 2009 .

[17]  Allan J. Delaney,et al.  Dielectric properties of soils at UHF and microwave frequencies 36R. J. Geophys. Res. V79, N11, Apr. 1974, P1699–1708 , 1974 .

[18]  Fawwaz T. Ulaby,et al.  Dielectric properties of soils in the 0.3-1.3-GHz range , 1995, IEEE Trans. Geosci. Remote. Sens..

[19]  Stefan Bouckaert,et al.  Non-intrusive aggregation in wireless sensor networks , 2011, Ad Hoc Networks.