Bandpass calibration of a wideband spectrometer using coherent pulse injection

Abstract

We present a relatively simple time domain method for determining the bandpass response of a system by injecting a nanosecond pulse and capturing the system voltage output. A pulse of sub-nanosecond duration contains all frequency components with nearly constant amplitude up to 1 GHz. Hence, this method can accurately determine the system bandpass response to a broadband signal. In a novel variation on this impulse response method, a train of pulses is coherently accumulated providing precision calibration with a simple system. The basic concept is demonstrated using a pulse generator-accumulator setup realised in a Bedlam board which is a high speed digital signal processing unit. The same system was used at the Parkes radio telescope between 2-13 October 2013 and we demonstrate its powerful diagnostic capability. We also present some initial test data from this experiment.

11 pages, 9 figures, submitted to Experimental Astronomy

References in corpus (3)

• Cosmological implications of baryon acoustic oscillation (BAO) measurements
• A lunar radio experiment with the Parkes radio telescope for the LUNASKA project
• Noise statistics in a fast digital radio receiver: the Bedlam backend for the Parkes Radio Telescope

Cited by in corpus (4)

• Data Analysis for Precision 21 cm Cosmology
• The Impact of Modeling Errors on Interferometer Calibration for 21 cm Power Spectra
• SARAS 2: A Spectral Radiometer for probing Cosmic Dawn and the Epoch of Reionization through detection of the global 21 cm signal
• A Digital Calibration Source for 21cm Cosmology Telescopes