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arXiv · 1702.04728

CHIME FRB: An application of FFT beamforming for a radio telescope

C. Ng·K. Vanderlinde·A. Paradise·P. Klages·K. Masui·K. Smith·K. Bandura·P. J. Boyle·M. Dobbs·V. Kaspi·A. Renard·J. R. Shaw·I. Stairs·I. Tretyakov
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Abstract

We have developed FFT beamforming techniques for the CHIME radio telescope, to search for and localize the astrophysical signals from Fast Radio Bursts (FRBs) over a large instantaneous field-of-view (FOV) while maintaining the full angular resolution of CHIME. We implement a hybrid beamforming pipeline in a GPU correlator, synthesizing 256 FFT-formed beams in the North-South direction by four formed beams along East-West via exact phasing, tiling a sky area of ~250 square degrees. A zero-padding approximation is employed to improve chromatic beam alignment across the wide bandwidth of 400 to 800 MHz. We up-channelize the data in order to achieve fine spectral resolution of $Δν$=24 kHz and time cadence of 0.983 ms, desirable for detecting transient and dispersed signals such as those from FRBs.

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C. Ng, K. Vanderlinde, A. Paradise, P. Klages, K. Masui, K. Smith, K. Bandura, P. J. Boyle, M. Dobbs, V. Kaspi, A. Renard, J. R. Shaw, I. Stairs, I. Tretyakov. 2017-02-15. CHIME FRB: An application of FFT beamforming for a radio telescope. https://doi.org/10.23919/ursigass.2017.8105318

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