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Related papers: Scintillation-Induced Intermittency in SETI

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Interstellar signals might be intermittent for many reasons, such as targeted sequential transmissions, or isotropic broadcasts that are not on continuously, or many other reasons. The time interval between such signals would be important,…

Instrumentation and Methods for Astrophysics · Physics 2021-10-26 Robert H. Gray

To date, the search for radio technosignatures has focused on sky location as a primary discriminant between technosignature candidates and anthropogenic radio frequency interference (RFI). In this work, we investigate the possibility of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-19 Bryan Brzycki , Andrew P. V. Siemion , Imke de Pater , James M. Cordes , Vishal Gajjar , Brian Lacki , Sofia Sheikh

This paper reports new, more sensitive observations of nine of the eleven extrastatistical signals in the Megachannel Extraterrestrial Assay (META). These extrastatistical signals had all of the expected characteristics of a transmission…

Astrophysics · Physics 2009-11-07 T. Joseph W. Lazio , Jill Tarter , Peter R. Backus

Previous and ongoing searches for extraterrestrial optical and infrared nanosecond laser pulses and narrow line-width continuous emissions have so far returned null results. At the commonly used observation cadence of $\sim 10^{-9}\,$s,…

Instrumentation and Methods for Astrophysics · Physics 2018-12-12 Michael Hippke

In the cm-wavelength range, an extraterrestrial electromagnetic narrow band (sine wave) beacon is an excellent choice to get alien attention across interstellar distances because 1) it is not strongly affected by interstellar /…

Instrumentation and Methods for Astrophysics · Physics 2018-05-08 G. R. Harp , R. F. Ackermann , Samantha K. Blair , J. Arbunich , P. R. Backus , J. C. Tarter , the ATA Team

We develop the theory of interstellar scintillation as caused by an irregular plasma having a power-law spatial density spectrum with a spectral exponent of 4 corresponding to a medium with abrupt changes in its density. An ``outer scale''…

Astrophysics · Physics 2009-10-31 Hendrik Lambert , Barney Rickett

We report a novel radio autocorrelation (AC) search for extraterrestrial intelligence (SETI). For selected frequencies across the terrestrial microwave window (1-10 GHz) observations were conducted at the Allen Telescope Array to identify…

Long baseline radio interferometers can provide some interesting opportunities for future SETI searches. Known advantages (compared to single dishes or beam-formed arrays), include the large reduction in false-positives due to the…

Instrumentation and Methods for Astrophysics · Physics 2018-10-18 M. A. Garrett

The search for extraterrestrial intelligence (SETI) is a scientific endeavor which struggles with unique issues -- a strong indeterminacy in what data to look for and when to do so. This has led to attempts at finding both fundamental…

Information Theory · Computer Science 2021-07-22 Ian George , Xinan Chen , Lav R. Varshney

The lack of evidence for the existence of extraterrestrial life, even the simplest forms of animal life, makes it is difficult to decide whether the search for extraterrestrial intelligence (SETI) is more a high-risk, high-payoff endeavor…

Popular Physics · Physics 2017-04-14 Claudio Grimaldi

The Doppler shift of a radio signal is caused by the relative motion between the transmitter and receiver. The change in frequency of the signal over time is called drift rate. In the studies of radio SETI (Search for Extraterrestrial…

Instrumentation and Methods for Astrophysics · Physics 2022-10-14 Jian-Kang Li , Haichen Zhao , Zhenzhao Tao , Tong-Jie Zhang , Sun Xiaohui

Searches for radio technosignatures place constraints on the prevalence of extraterrestrial transmitters in our Galaxy and beyond. It is important to account for the complete stellar population captured within a radio telescope's field of…

Instrumentation and Methods for Astrophysics · Physics 2025-11-26 Louisa A. Mason , Michael A. Garrett , Andrew P. V. Siemion

The Search for Extraterrestrial Intelligence (ETI) is, historically, a search for aliens like us, inspired by human centric ideas of intelligence and technology. However, humans are not the only instance of an intelligent, communicating…

Instrumentation and Methods for Astrophysics · Physics 2025-11-11 Cameron Brooks , Estelle Janin , Gage Siebert , Cole Mathis , Orit Peleg , Sara Imari Walker

The Search for Extra-terrestrial Intelligence (SETI) aims to find technological signals of extra-solar origin. Radio frequency SETI is characterized by large unlabeled datasets and complex interference environment. The infinite…

Instrumentation and Methods for Astrophysics · Physics 2019-01-16 Yunfan Gerry Zhang , Ki Hyun Won , Seung Woo Son , Andrew Siemion , Steve Croft

Observations over the last two decades have shown that a significant fraction of all flat-spectrum, extragalactic radio sources exhibit flux density variations on timescales of a day or less at frequencies of several GHz. It has been…

Interstellar scintillation analysis of pulsars allows us to probe the small-scale distribution and inhomogeneities of the ionized interstellar medium. Our priority is to present the data set and the basic measurements of scintillation…

The Search for Extraterrestrial Intelligence (SETI) attempts to address the possibility of the presence of technological civilizations beyond the Earth. Benefiting from high sensitivity, large sky coverage, an innovative feed cabin for…

Interstellar scintillation (ISS) has been established as the cause of the random variations seen at centimetre wavelengths in many compact radio sources on timescales of a day or less. Observations of ISS can be used to probe structure both…

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

Astrophysics · Physics 2007-05-23 J. M. Cordes

The "search for extraterrestrial intelligence" (SETI) commensal surveys aim to scan the sky to find possible technosignatures from the extraterrestrial intelligence (ETI). The mitigation of radio frequency interference (RFI) is an important…

Instrumentation and Methods for Astrophysics · Physics 2023-08-21 Yu-Chen Wang , Zhen-Zhao Tao , Zhi-Song Zhang , Cheqiu Lyu , Tingting Zhang , Tong-Jie Zhang , Dan Werthimer
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