Symbol repetition in interstellar communications: methods and observations

TL;DR

This study investigates the presence of symbol repetition in interstellar communication signals using radio telescope observations, proposing methods to detect distinct signal characteristics that could indicate extraterrestrial origin.

Contribution

The paper introduces a novel experimental approach to detect symbol repetition in interstellar signals, building on previous hypotheses and observations with new data from a 143-day radio telescope survey.

Findings

Detection of apparent symbol repetition in specific celestial directions.

No significant variation across different Right Ascension ranges.

Anomalous signals observed near specific celestial coordinates.

Abstract

Discoverable interstellar communication signals are expected to exhibit al least one signal characteristic clearly distinct from random noise. A hypothesis is proposed that radio telescope received signals may contain transmitted delta-t delta-f opposite circular polarized pulse pairs, conveying a combination of information content and discovery methods, including symbol repetition. Hypothetical signals are experimentally measured using a 26 foot diameter radio telescope, a chosen matched filter receiver, and machine post processing system. Measurements are expected to present likelihoods explained by an Additive White Gaussian Noise model, augmented to reduce radio frequency interference. In addition, measurements are expected to present no significant differences across a population of Right Ascension ranges, during long duration experiments. The hypothesis and experimental methods described in this paper are based on multiple radio telescope delta-t delta-f polarized pulse pair experiments previously reported. (ref. arXiv:2105.03727, arXiv:2106.10168). In the current work, a Right Ascension filter spans twenty-one 0.3 hour Right Ascension bins over a 0 to 6.3 hr range, during a 143 day experiment. Apparent symbol repetition is measured and analyzed. The 5.25 plus or minus 0.15 hr Right Ascension, -7.6 degree plus or minus 1 degree Declination celestial direction has been associated with anomalous observations in previous work, and continues to present anomalies, having unknown cause.