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arXiv · 1502.05862

Bandpass calibration of a wideband spectrometer using coherent pulse injection

Nipanjana Patra·Justin D. Bray·Paul Roberts·Ron D. Ekers
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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.

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Nipanjana Patra, Justin D. Bray, Paul Roberts, Ron D. Ekers. 2015-02-20. Bandpass calibration of a wideband spectrometer using coherent pulse injection. https://doi.org/10.1007/s10686-017-9523-8

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