Spectrum Sharing in Weather Radar Networked System: Design and Experimentation

Abstract

Weather radar networked system (WRNS) is composed of multiple weather radars that transmit a radio signal and receive an echo signal reflected by weather targets. In the current form of WRNS, each radar exploits a different non-orthogonal frequency band, which leads to inefficiency in frequency usage. To tackle this issue, we propose a novel frequency-shared WRNS and investigate its feasibility via actual experiments. The challenges in a frequency-shared WRNS lie in mitigating: 1) interference from other radars (inter-site interference) and 2) interference from nearby scatterers (intra-site interference). To mitigate inter-site interference, we modulate a waveform with an orthogonal code and conduct matched filtering. To mitigate intra-site interference, we adopt an interference-aware sidelobe suppression algorithm and integrate the algorithm with a novel algorithm having an adaptive configuration. We have implemented a prototype of the proposed WRNS using X-band radars and a MATLAB-based signal processing module. An experimental study using this prototype shows that estimation errors are less than those required by a commercial weather radar (WSR-88D) when 10 radars operate with in the same frequency band. To the best of our knowledge, this paper is the first to implement a prototype for frequency-shared WRNS and explore the feasibility of frequency sharing among weather radars via experimentation with real weather radars.