Plant Doctor: Harnessing Backscatter Radio Sensors for Agriculture

WINLAB Summer Internship 2024
Group Members: Sam-Fone Cheung & Shriya Das
Advisor: Aggelos Bletsas

Project Objective

Backscatter radio, or reflection radio, offers a low-cost and low-power alternative to conventional radio sensor networks. This is crucial for modern agriculture which requires continual monitoring of environmental conditions such as soil moisture or temperature. Prior research using capacitance sensors to measure soil moisture has shown promising results using backscatter radio, despite the limited range.

Our group expanded this work to use temperature sensors on a plants which will transmit information using a network of RFID tags. These sensors should be battery-less and low-cost as they will harvest ambient radio frequency (RF) energy.

Weekly Progress

WEEK ONE

​Weekly Presentation
Progress: Read prior art about ​backscatter radios, RFID (radio frequency identification) tags, and using ​capacitance sensors to measure soil moisture.

WEEK TWO

​Weekly Presentation
Progress: Used RTL-SDR's to explore software-defined radios (SDR) and tune into local FM stations. Also familiarized ourselves with ​GNURadio.

WEEK THREE

​Weekly Presentation
Progress: Continued using GNURadio to implement ​frequency shift keying and ​periodograms (maximum likelihood estimators). We also used MATLAB/Octave to compare our results from GNURadio using the SDR.

WEEK FOUR

[Weekly Presentation]
Progress: Explored the accuracy of the reciever while changing the power transmission, frequency, and distance between the SDR and signal generator. Learned about matched filters and how to ​implement them into the receiver.