English
Related papers

Related papers: Interferometer measurements in interstellar commun…

200 papers

Astronomers usually need the highest angular resolution possible, but the blurring effect of diffraction imposes a fundamental limit on the image quality from any single telescope. Interferometry allows light collected at widely-separated…

Instrumentation and Methods for Astrophysics · Physics 2015-05-20 John D. Monnier , Ronald J. Allen

We are performing a transient, microsecond timescale radio sky survey, called "Astropulse," using the Arecibo telescope. Astropulse searches for brief (0.4 {\mu}s to 204.8 {\mu}s), wideband (relative to its 2.5 MHz bandwidth) radio pulses…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 J. Von Korff , P. Demorest , E. Heien , E. Korpela , D. Werthimer , J. Cobb , M. Lebofsky , D. Anderson , B. Bankay , A. Siemion

With the advent of optical interferometers that will be coming online in the next decade, radial velocity searches for extra-solar planets will be complemented by high angular resolution astrometric measurements. In this paper, we explore…

Astrophysics · Physics 2009-11-06 J. A. Eisner , S. R. Kulkarni

The sky-averaged, or global, background of redshifted $21$ cm radiation is expected to be a rich source of information on cosmological reheating and reionizaton. However, measuring the signal is technically challenging: one must extract a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-03 Tejaswi Venumadhav , Tzu-Ching Chang , Olivier Doré , Christopher M. Hirata

We have made observations of 98 low-Galactic-latitude pulsars to measure pulse broadening caused by multipath propagation through the interstellar medium. Data were collected with the 305-m Arecibo telescope at four radio frequencies…

The non transparency and severe propagation effects of the terrestrial ionosphere make it impossible for Earth based instruments to study the universe at low radio frequencies. An exploration of the low frequency radio window with the…

Astrophysics · Physics 2007-05-23 Divya Oberoi , Jean-Louis Pinçon

Signals from radio pulsars show a wavelength-dependent delay due to dispersion in the interstellar plasma. At a typical observing wavelength, this delay can vary by tens of microseconds on five-year time scales, far in excess of signals of…

In this paper, we propose a novel method for distinguishing extraterrestrial intelligence (ETI) signals from radio frequency interference (RFI) by leveraging polarization features. We exploit the sinusoidal variation of the linearly…

Instrumentation and Methods for Astrophysics · Physics 2023-12-08 Jian-Kang Li , Yu Chen , Zhen-Zhao Tao , Xiao-Hang Luan , Tong-Jie Zhang , Bo-Lun Huang , Xiao-Hui Sun , Vishal Gajjar

Precision phase readout of optical beat note signals is one of the core techniques required for intersatellite laser interferometry. Future space based gravitational wave detectors like eLISA require such a readout over a wide range of MHz…

Pulsars with periods more than 0.4 seconds in the declination range -9o < decj < 42o and in the right ascension range 0h < r.a.< 24h were searched in parallel with the program of interplanetary scintillations monitoring of a large number of…

We consider interstellar scintillations as a cause of intermittency in radio signals from extraterrestrial intelligence (ETI). We demonstrate that scintillations are very likely to allow initial detections of narrowband signals from distant…

Astrophysics · Physics 2009-10-30 James M. Cordes , T. Joseph W. Lazio , Carl Sagan

The Search for Extraterrestrial Intelligence aims to find evidence of technosignatures, which can point toward the possible existence of technologically advanced extraterrestrial life. Radio signals similar to those engineered on Earth may…

The Exoplanet Tracker is a prototype of a new type of fibre-fed instrument for performing high precision relative Doppler measurements to detect extra-solar planets. A combination of Michelson interferometer and medium resolution…

Astrophysics · Physics 2009-11-10 J. C. van Eyken , J. Ge , S. Mahadevan , C. DeWitt

We demonstrate the ability to measure precise stellar barycentric radial velocities with the dispersed fixed-delay interferometer technique using the Exoplanet Tracker (ET), an instrument primarily designed for precision differential…

The design of a downlink communication system for returning scientific data from an interstellar flyby probe is reviewed in this tutorial white paper. It its assumed that the probe is ballistic, and data is downloaded during a period…

Instrumentation and Methods for Astrophysics · Physics 2023-06-26 David Messerschmitt , Philip Lubin , Ian Morrison

We show that distances of objects at cosmological distances can be measured directly using interferometry. Our approach to interferometric parallax comes from analysis of 4-point amplitude and intensity correlations that can be generated…

Astrophysics · Physics 2008-11-26 Pankaj Jain , John P. Ralston

Radio interferometers can measure the full polarization state of incoming waves by cross--correlating all combinations of two orthogonal polarizations at each antenna. The independent sets of electronics used to detect the two polarization…

Instrumentation and Methods for Astrophysics · Physics 2012-05-18 W. D. Cotton

The microhertz frequency band of gravitational waves probes the merger of supermassive black holes as well as many other gravitational wave phenomena. However, space-interferometry methods that use test masses would require further…

Instrumentation and Methods for Astrophysics · Physics 2025-09-29 Matthew McQuinn , Casey McGrath

A number of radio interferometers are currently being planned or constructed to observe 21 cm emission from reionization. Not only will such measurements provide a detailed view of that epoch, but, since the 21 cm emission also traces the…