RASDRviewer: RASDR2 Control and Analysis Software

Paul Oxley, David Fields, Stan Kurtz

ABSTRACT

The Radio Astronomy Software Defined Receiver (RASDR) is a system that provides a versatile Software-Defined Receiver (SDR) that is optimized for Radio Astronomy. RASDR2 is the current hardware that is in testing with a planned general release at this conference. See multiple other presentations at this conference as well as previous SARA Journals and Proceedings publications for the history of this SARA project.
RASDRviewer is the software that controls RASDR2 and presents captured data to the user. It uses a Windows based GUI that is designed for portability to both the Linux and MAC platforms. This portability is mainly based on the use of the wxWidgets development tool that is available as open source freeware. wxWidgets abstracts most of the common graphical window objects to a common language that is applicable across all of the platforms. Thus the look and feel of the user experience is the same regardless of the platform being used. Loading and using RASDRviewer on a Windows operating system is straightforward.
This paper describes the RASDRviewer software and documents some of the experiences in its implementation. A brief discussion of the Windows Driver and FX3 firmware is also included.
RASDRviewer is an extension of the Lime Microsystems FFTviewer to optimize radio astronomy functionality. The original FFTviewer presented three charts, I & Q samples vs time, I vs Q for system verification and an output display showing results of a large Fast Fourier Transform (FFT) that operates in near real time. The FFT is capable of delivering up to 16,384 frequency bins multiple times per second. The control of the system required knowledge of the Lime chip architecture and RF engineering theory.
For RASDRviewer, modifications have been made to customize the software for Radio Astronomy use. This includes optimization of control functions for radio astronomy use, addition of a Power vs Time plot, file outputs and inclusion of a simplified selection of the user options. In addition, RASDRviewer makes full use of the receive capabilities of the Lime Chip including sample rates up to 32 M Samples/Second and 28 MHz of bandwidth. RASDRviewer is being demonstrated at this conference. The demonstration will include real-time control of RASDR2 to produce three dimensional FFT plots. A copy of the software executable is included in the CD for this meeting. The source code will be made available to anyone who requests a copy and is willing to be coached through the setup of the compiling environment.