Noise statistics in a fast digital radio receiver: the Bedlam backend for the Parkes Radio Telescope

TL;DR

This paper analyzes how digital processing affects the statistical properties of signals in radio telescopes, using Bedlam backend data to improve transient event detection accuracy.

Contribution

It provides a detailed analysis of noise statistics in a digital radio receiver and demonstrates the effects with experimental results from the Bedlam backend.

Findings

Modified signal statistics due to digital processing are characterized.

Experimental validation with Bedlam backend data.

Implications for transient detection significance.

Abstract

The digital record of the voltage in a radio telescope receiver, after frequency conversion and sampling at a finite rate, is not a perfect representation of the original analog signal. To detect and characterise a transient event with a duration comparable to the inverse bandwidth it is necessary to compensate for these effects, which modifies the statistics of the signal, making it difficult to determine the significance of a potential detection. We present an analysis of these modified statistics and demonstrate them with experimental results from Bedlam, a new digital backend for the Parkes radio telescope.