Pseudo-Real-Time Signal Visualization during Pulsar Observations on the Green Bank Telescope

C.J. Kelly, K O'Neil (NRAO-Greenbank)


When using the Robert C. Byrd Green Bank Telescope (GBT) for pulsar observations, observers need to be able to insure the data reaching the observer is of the highest quality possible. To do this, telescope users need to be able to monitor, in real time, the raw signal intensity of data as it flows in from the GBT. In the summer of 2004 at NRAO-Greenbank, my Research Experience For Teachers project was spent developing this utility. For portability and compatibility, the computer language python was used to build the visualization utility. The major hurdle in developing the python modules was in reading and manipulating the tremendous quantity of unprocessed data acquired during an observation. (The spigot data rate is set to be 25 Mb/s.) The data stream is intercepted by a "spigot" card, buffered and then stored on a hard drive as a series of binary files. The python modules attempt to read, parse and organize these binary files to ultimately produce a simple intensity versus time plot of the data stream. The modules developed run as a loop to update the plot several times per minute. Integrating the knowledge and experience of this research in the classroom involves an introductory unit on radio astronomy and astrophysics. Additionally, students will have the opportunity to analyze data collected from the Crab Nebula Pulsar and experience backend processes such as data folding. These activities will be described. This work was funded by the National Science Foundation RET program.

Poster - .jpg (1.2 Mb)