Design of Software Defined Radio for SuperDARN Radar
Software defined radio (SDR) is a rapidly developing field enabled by continuing improvements in digital electronics. Software defined radio has been used extensively in communication systems due to its flexibility and cost effectiveness. Recently, SDR has been incorporated into radar systems, particularly for ionospheric research. This study investigated the benefits and design of a high frequency (HF) SDR receiver for the next generation of Super Dual Auroral Network (SuperDARN) radars. This work analyzed digital beamforming and waveform design approaches that would be enabled by the adoption of a SDR based radar design and found that these techniques could improve the performance of SuperDARN radars. This work also developed a prototype receiver to demonstrate the feasibility of a SDR based SuperDARN radar. The hardware selection for this receiver leveraged low-cost commercial off-the-shelf software defined radios and amplifier designs supplemented by custom filters. The software implementation utilized GNU Radio, an open source SDR and signal processing platform, to process and record receiver data. A prototype was successfully designed and constructed using the Red Pitaya software defined radio. This prototype included a 4 channel receiver which was evaluated in the laboratory setting and tested at the Blackstone, Virginia radar site. A comparison of results from the prototype receiver and the existing hardware showed promise for the use of this platform in future ionospheric research.