Radio Astronomy with RASDR2 and RASDRviewer

D. Fields, P. Oxley, B. Vacaliuc, C. Lyster , S. Kurtz, Z. Tamosevicius and S. Berl
Tamke-Allan Observatory
Roane State Community College
276 Patton Lane
Harriman, TN 37748 

ABSTRACT

The RASDR design team is releasing a software-defined receiver (SDR) for radio astronomy called RASDR2. The receiver consists of two high-density circuit boards -- a wide-band femtocell chip on the front end analog interface MyriadRF board linked to a DigiRed digitization and function control board -- coupled to a computer via either a USB2 or USB3 interface. RASDRViewer software runs in a Windows environment and performs receiver control, FFT analysis, spectrum averaging, power monitoring and other functions. Depending on the specific application, RASDR2 is used with an antenna, filter, preamplifier, optional upconversion or system control devices, and external frequency/time reference signals. The team has three RASDR2 units in operation and is working to make units available to SARA members.

This presentation covers RASDR2 application to solve some common experimental challenges encountered by members of the community of amateur radio astronomers. Results of operation in several RF spectral bands will be shown and discussed. These results include monitoring HI emissions from distant clouds, interfacing to the NRAO 40’ radio telescope to record spectral data; interfacing to the NRAO 20m radio telescope to record and extract information from data taken at different observing sessions; monitoring a 10MHz section of the commercial FM band with a wire antenna; and monitoring a section of the crowded HF short wave band with a wire antenna. The use of upconverters is discussed. Software analysis was done with RASDRwindows, Excel, and Python. [NRAO 40’ and 20m results are omitted from this version of the paper but were discussed in the presentation. They will be documented separately.]

Details of RASDR2 software, firmware and basic hardware are discussed in other conference presentations.