scholarly journals Eavesdropping Detection of Radio Signals from Other Planets, with One Bit-Implementation Techniques Using Existing Computers

1985 ◽  
Vol 112 ◽  
pp. 335-339
Author(s):  
Stephen H. Knowles
Keyword(s):  
Spectral Analysis ◽  
Doppler Shift ◽  
General Purpose ◽  
Analysis Techniques ◽  
First Derivative ◽  
Implementation Techniques ◽  
Radio Signals ◽  
Eavesdropping Detection

Detection of other civilizations by “eavesdropping” on accidental radiation from television and other self-oriented signals is proposed. One-bit spectral analysis techniques to implement this are discussed. These can utilize existing general-purpose computers, and provide flexibility of strategy in the analysis. The first derivative of doppler shift from an unknown planet can be compensated for with increased integration times possible.

Investigation Of Pre-Earthquake Ionospheric Anomalies Before Albania 2019 Earthquake Using The Romanian Receivers Of The Vlf/Lf Infrep And Gnss Global European Networks

2020 ◽  
Author(s):  
Iren Adelina Moldovan ◽  
Victorin Emilian Toader ◽  
Christina Oikonomou ◽  
Haris Haralambous ◽  
Pier Francesco Biagi ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Seismic Event ◽  
Global Network ◽  
Electron Content ◽  
European Network ◽  
Total Electron ◽  
Ionospheric Perturbations ◽  
Analysis Techniques ◽  
Radio Signals ◽  
Significant Effort

<p>The last two decades a significant effort has been invested in order to understand and interpret the link between seismic activity and ionospheric perturbations. Since not any individual seismo-ionospheric precursor can be used as an accurate stand alone for earthquake prediction it is required to integrate different kinds of precursors and analysis techniques.</p><p>To this context, the aim of this study is to investigate pre-earthquake ionospheric anomalies that occurred prior to large 6.4 Mw earthquake in Albania (26<sup>th</sup> November 2019), following a multi-instrument and multi-technique approach, using subionospheric radio VLF/LF signals obtained from the Romanian receivers of the INFREP European network and Total Electron Content (TEC) observations from GNSS global network.</p><p>To identify possible ionospheric anomalies before the earthquakes we applied the terminator time and nighttime fluctuation methods on the amplitude of subionospheric LF radio signals and spectral analysis on diurnal TEC variations several days prior the seismic event. It was found that sunrise terminator times are delayed approximately 20-40 min few days before and during the earthquake day. Intensified wave-like TEC oscillations with periods around 20 min were also revealed up to 5 days prior to the earthquake shocks in all cases that could be interpreted as possible ionospheric precursors of the impending earthquakes.      </p>

scholarly journals Relationship between precursory signals and corresponding earthquakes using different spectral analysis techniques

2021 ◽  
pp. 101338
Author(s):  
Ghada Ali ◽  
Ali G. Hafez ◽  
El-Sayed Soliman A. Said ◽  
Kamal Abdelrahman ◽  
Elkhedr Ibrahim ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Analysis Techniques

scholarly journals Doppler Shift of Radio Signals Transmitted between Orbiting Satellites

1982 ◽  
Vol 35 (2) ◽  
pp. 155 ◽  
Author(s):  
PL Dyson ◽  
JA Bennett
Keyword(s):  
Electron Concentration ◽  
Doppler Shift ◽  
Rate Of Change ◽  
Line Of Sight ◽  
Concentration Gradients ◽  
Mean Velocity ◽  
Radio Signals ◽  
The Mean ◽  
The Moment ◽  
The Individual

A general expression, applicable at VHF and above, is derived for the Doppler shift of radio signals transmitted between two satellites embedded in the ionosphere. The Doppler shift is made up of several contributions which depend on (a) the rate of change of the free space path between the satellites, (b) the components, perpendicular to the line of sight between the satellites, of both the mean velocity of the satellites and the electron concentration gradients, (c) the moment of the perpendicular electron concentration gradients and the deviations from the mean of the individual satellite perpendicular velocities, (d) the velocity components along the line of sight between the satellites, and the electron concentration values at each satellite, and (e) changes occurring in the ionosphere with time.

An Overview of Methods for Automatic Reassembly of Fragmented Objects

2011 ◽  
pp. 263-288
Author(s):  
Dimitris Arabadjis ◽  
Michael Exarhos ◽  
Fotios Giannopoulos ◽  
Solomon Zannos ◽  
Panayiotis Rousopoulos ◽  
...  
Keyword(s):  
Signal Processing ◽  
Pattern Analysis ◽  
Complete System ◽  
General Purpose ◽  
Wall Paintings ◽  
Analysis Techniques ◽  
Application Problem ◽  
Archaeological Objects

In this chapter the authors outline some research works characteristic for the application of Signal Processing and Pattern Analysis techniques to the automatic reconstruction / reassembly of fragmented archaeological objects. The studies described in the chapter cover in their application cases a variety of archaeological objects, ranging from documents and wall-paintings to pots and sculptures. Moreover there are distinct approaches in the treatment of these application cases, with some works focusing on the development of a reconstruction methodology of general purpose, while others aim to develop a complete system to treat a specific application problem. The methodologies developed in these studies are outlined in the chapter so as to retain the basic technical elements of each approach that compile the proposed reconstruction algorithmic scheme.

Stellar parameters with FASMA: a new spectral synthesis package

2017 ◽  
Vol 12 (S330) ◽  
pp. 271-272
Author(s):  
M. Tsantaki ◽  
D. T. Andreasen ◽  
G. D. C. Teixeira ◽  
S. G. Sousa ◽  
N. C. Santos ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Spectral Synthesis ◽  
Computational Time ◽  
Spectral Information ◽  
Atmospheric Parameters ◽  
Chemical Abundances ◽  
Analysis Techniques ◽  
Medium Resolution ◽  
Similar Accuracy ◽  
Temperature Surface

AbstractCurrent Galactic surveys, including the Gaia mission, rely on the efficiency of the spectral analysis techniques to provide precise and accurate spectral information (i.e. effective temperature, surface gravity, metallicity, and chemical abundances) in the shortest computational time. In this work, we present a new package to preform complete spectral analyses based on the spectral synthesis technique (Tsantaki et al. 2017, submitted). We focus on deriving atmospheric parameters for FGK-type stars using both high and medium resolution (GIRAFFE) spectra. This method is implemented on the Gaia-ESO benchmark stars to confirm its validity, achieving similar accuracy for the two resolution setups.

ROBFIT: A general purpose spectral analysis package

1990 ◽  
Author(s):  
G. J. Bamford ◽  
R. L. Coldwell ◽  
A. C. Rester
Keyword(s):  
Spectral Analysis ◽  
General Purpose ◽  
Analysis Package
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