RFThermometer: A Temperature Estimation System with Commercial UHF RFID Tags

RFID-based sensors have attracted great interest due to the wide employment of RFID tags, ease of deployment, and low cost. However, most RFID-based sensors rely on hardware modification, which increases the cost and hampers the deployment. In this paper, we propose RFThermometer, a temperature estimation system with commercial UHF RFID tags. We first study the effect of temperature on RFID phase. To mitigate the problem caused by missing phase measurements, we propose a tensor completion method to restore missing phases and a Gaussian Process (GP) model for building phase-temperature maps in the offline stage. A dynamic time warping based greedy method is proposed to estimate the unknown temperature in the online stage. Experimental results verify the performance of RFThermometer.