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Extraterrestrial communication signals are hypothesized to be present in an extensive search space. Using principles of communication theory and system design, methods are studied and implemented to reduce the signal search space, while…

Signal Processing · Electrical Eng. & Systems 2024-04-16 William J. Crilly

We present a study of water vapour in the Venus troposphere obtained by modelling specific water vapour absorption bands within the 1.18 \mu m window. We compare the results with the normal technique of obtaining the abundance by matching…

Earth and Planetary Astrophysics · Physics 2012-12-06 S. Chamberlain , J. A. Bailey , D. Crisp , V. S. Meadows

Atmospheric water vapor is the main limiting factor of atmospheric transparency in the mm and submm wavelength spectral windows. Thus, dry sites are needed for the installation and successful operation of radio astronomy observatories…

In time-domain radio astronomy with arrays, voltages from individual antennas are added together with proper delay and fringe correction to form the beam in real-time. In order to achieve the correct phased addition of antenna voltages one…

Instrumentation and Methods for Astrophysics · Physics 2024-07-11 Sanjay Kudale , Jayanta Roy , Jayaram N. Chengalur , Shyam Sharma , Sangita Kumari

M star spectra, at wavelengths beyond 1.35 $\mu$m, are dominated by water vapour yet terrestrial water vapour makes it notoriously difficult to make accurate measurement from ground-based observations. We have used the short wavelength…

Astrophysics · Physics 2009-11-07 Hugh R. A. Jones , Yakiv Pavlenko , Serena Viti , Jonathan Tennyson

Over the last decades, radio detection of air showers has been established as a promising detection technique for ultrahigh-energy cosmic rays and neutrinos. Very large or dense antenna arrays are necessary to be proficient at collecting…

Instrumentation and Methods for Astrophysics · Physics 2018-11-28 Anne Zilles , Olivier Martineau-Huynh , Kumiko Kotera , Matias Tueros , Krijn de Vries , Washington Carvalho , Valentin Niess

Digital radio antenna arrays, like LOPES (LOFAR PrototypE Station), detect high-energy cosmic rays via the radio emission from atmospheric extensive air showers. LOPES is an array of dipole antennas placed within and triggered by the…

Instrumentation and Methods for Astrophysics · Physics 2012-05-14 F. G. Schröder , T. Asch , L. Bähren , J. Blümer , H. Bozdog , H. Falcke , A. Haungs , A. Horneffer , T. Huege , P. G. Isar , O. Krömer , S. Nehls

In the millimeter wave (30-300 GHz) and Terahertz (0.1-10 THz) frequency bands, high spreading loss and molecular absorption often limit the signal transmission distance and coverage range. In this paper, four directions to tackle the…

Signal Processing · Electrical Eng. & Systems 2019-02-14 Ian F. Akyildiz , Chong Han , Shuai Nie

In order for telescopes to obtain good and precise images they need to see through atmospheric turbulence. To accomplish this and compensate for atmospheric turbulence we use Adaptive Optics technologies. In this thesis we analyze the…

Instrumentation and Methods for Astrophysics · Physics 2023-10-13 Cesar Laguna

The calibration and traceability of high resolution frequency modulated continuous wave (FMCW) ladar sources is a requirement for their use in length and volume metrology. We report the calibration of a FMCW ladar length measurement system…

Optics · Physics 2015-03-03 Ana Baselga Mateo , Zeb W. Barber

Fiber-delay measurement is one of the key fundamental technologies in numerous fields. Here we propose and experimentally demonstrate a high-precision and concise optical time delay measurement system based on the technique of linear…

Optics · Physics 2023-12-19 Yufei Zhang , Ziyang Chen , Dongrui Yu , Jialin Niu , Xing Chen , Hong Guo

We demonstrated a simple technique for monitoring range variation with millimeter-precision between two remote sites using off-the-shelf wireless communication modules. The need for the flexible positioning of wireless devices is…

Signal Processing · Electrical Eng. & Systems 2018-10-31 Bhola R. Panta , Kohta Kido , Satoshi Yasuda , Yuko Hanado , Seiji Kawamura , Hiroshi Hanado , Kenichi Takizawa , Masugi Inoue , Nobuyasu Shiga

Recent detections of high-redshift absorption by both atomic hydrogen and molecular gas in the radio spectra of quasars have provided a powerful tool to measure possible temporal and spatial variations of physical `constants' in the…

Astrophysics · Physics 2009-10-30 M. J. Drinkwater , J. K. Webb , J. D. Barrow , V. V. Flambaum

Long-period radio transients (LPTs) are a recently identified phenomenon that challenge our current understanding of compact objects and coherent radio emission mechanisms. These objects emit radio pulses similar to those of pulsars, but at…

In the detection of gravitational waves in space, the arm lengths between spacecraft are not equal due to their orbital motion. Consequently, the equal arm length Michelson interferometer used in Earth laboratories is not suitable for…

General Relativity and Quantum Cosmology · Physics 2024-06-21 Gang Wang

Terahertz-band (100 GHz-10 THz) communication is a promising radio technology envisioned to enable ultra-high data rate, reliable and low-latency wireless connectivity in next-generation wireless systems. However, the low transmission power…

Signal Processing · Electrical Eng. & Systems 2024-08-26 Priyangshu Sen , Sherif Badran , Vitaly Petrov , Arjun Singh , Josep M. Jornet

Over the past few decades, the development of cellular communication technology has spanned several generations in order to add sophisticated features in the updated versions. Moreover, different high-frequency bands are considered for…

The pattern of the radio emission of air showers is finely sampled with the Low-Frequency ARray (LOFAR). A set of 382 measured air showers is used to test a fast, analytic parameterization of the distribution of pulse powers. Using this…

The Pierre Auger Collaboration is exploring the potential of radio-detection techniques to measure the extensive air showers. The main advantage of these setups is the possibility to cover a large area with no atmospheric attenuation and…

Instrumentation and Methods for Astrophysics · Physics 2019-08-13 K. Louedec

Two optical fiber Mach-Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer with a length of 2 m optical fiber in each arm with the main direction of the…

Classical Physics · Physics 2015-05-14 Victor de Haan