Experimental Astronomy

, Volume 28, Issue 1, pp 25–60

A real-time software backend for the GMRT

  • Jayanta Roy
  • Yashwant Gupta
  • Ue-Li Pen
  • Jeffrey B. Peterson
  • Sanjay Kudale
  • Jitendra Kodilkar
Original Article

Abstract

The new era of software signal processing has a large impact on radio astronomy instrumentation. Our design and implementation of a 32 antennae, 33 MHz, dual polarization, fully real-time software backend for the GMRT, using only off-the-shelf components, is an example of this. We have built a correlator and a beamformer, using PCI-based ADC cards and a Linux cluster of 48 nodes with dual gigabit inter-node connectivity for real-time data transfer requirements. The highly optimized compute pipeline uses cache efficient, multi-threaded parallel code, with the aid of vectorized processing. This backend allows flexibility in final time and frequency resolutions, and the ability to implement algorithms for radio frequency interference rejection. Our approach has allowed relatively rapid development of a fairly sophisticated and flexible backend receiver system for the GMRT, which will greatly enhance the productivity of the telescope. In this paper we describe some of the first lights using this software processing pipeline. We believe this is the first instance of such a real-time observatory backend for an intermediate sized array like the GMRT.

Keywords

Radio interferometer Correlator Beamformer COTS High performance computing  Parallel processing RFI 

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Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • Jayanta Roy
    • 1
  • Yashwant Gupta
    • 1
  • Ue-Li Pen
    • 2
  • Jeffrey B. Peterson
    • 3
  • Sanjay Kudale
    • 1
  • Jitendra Kodilkar
    • 1
  1. 1.National Centre for Radio Astrophysics (NCRA), Tata Institute of Fundamental Research (TIFR)Pune University CampusPuneIndia
  2. 2.McLennan LaboratoriesCanadian Institute of Theoretical Astrophysics (CITA)TorontoCanada
  3. 3.Carnegie Mellon UniversityPittsburghUSA

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