Non-Gaussian Noise at the Output of a Resonant Gravitational Antenna in the Fast Filtering Regime. Information Aspect

The information characteristics of additive noise at the output of a resonant gravitational antenna are considered. Fisher information for the Explorer resonant gravitational antenna operating in the fast filtering regime is calculated under conditions of parametric a priori uncertainty from experimental data. The expediency is discussed of using an amplitude–frequency algorithm for suppressing correlated non-Gaussian noise when processing the output signal of a resonant gravitational antenna operating in this regime.     

A Gravitational Wave Detector Based on a Two-Cavity Laser Measurement System

Results are presented on detecting low-frequency periodic gravitational radiation from binary relativistic astrophysical objects. __________ Translated from Izmeritel'naya Tekhnika, No. 9, pp. 13–18, September, 2005.     

Frequency–Amplitude Suppression of Gravitational Antenna Noise in the “Fast Filtering” Regime

A predetector algorithm is considered for detecting weak gravitational pulses on a background of non-Gaussian noise at the output of resonant gravitational antennas with a displacement transformer. The algorithm is based on the frequency–amplitude suppression of additive noise under conditions of a priori uncertainty.     

Resonance gravitational antennas: Pulse interference

Resonant gravitational antennas with slow filtering are considered and characteristics are calculated for a parametric model for the a priori uncertainty in the class of ε-corrupted distributions in the presence of wide-band chaotic pulsed Poisson interference. __________ Translated from Izmeritel’naya Tekhnika, No. 5, pp. 5–8, May, 2006.     

Statistical Analysis of Coincidences in a Gravitational-Wave Experiment with Nonstationary Noise

A modified algorithm is considered for processing the output signal from a resonant gravitational antenna in the form of coincidences in a two-mode state of slow filtering in the presence of nonstationary interference.__________Translated from Izmeritel’naya Tekhnika, No. 6, pp. 11–13, June, 2005.     

Frequency and amplitude suppression of nongaussian noise at the output of a resonant gravitational antenna in slow filtering

The structure is considered for an inertial nonlinear whitening filter and the optimal characteristic for a fast nonlinear converter for frequency-amplitude suppression of multiplicative nongaussian noise at the output of a resonant gravitational antenna in slow filtering. __________ Translated from Izmeritel’naya Tekhnika, No. 3, pp. 8–11, March, 2006.     

Effect of the earth on measurement of the gravitation constant by a torsional balance

A procedure is developed for checking the effect of the Earth on measurement of the gravitational constant by a torsional balance. As a result of the study, it is established that the upper limit of screening is at the level of (2.0 ± 0.5)·10⁻¹³ cm²/g. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 3–5, June, 2006.     

Hypothesis Concerning an Electromagnetic Destabilizing Factor when Measuring the Gravitational Constant

A well-founded suggestion is made according to which the failures of numerous attempts to increase the accuracy of measuring the gravitational constant are a result of the influence of a change in the permanently existing background of low-frequency and extremely low-frequency electromagnetic fields (10^–3–10⁴ Hz) on the elastic properties of the suspension fiber of the torsion balance. Simple experiments are proposed in order to verify this hypothesis together with possible measures for increasing the stability of measurements.     

Properties of Perfluorobenzene near the Critical Point

The density of vapor and liquid perfluorobenzene along the liquid–vapor coexistence curve has been studied by a gamma-ray attenuation technique over the temperature range from 299 to 517 K. According to measurements, the coordinates of the critical point are T_C = 516.66 ± 0.05 K and ρ _C = 550.5 ± 2 kg · m⁻³. The critical exponent β of the coexistence curve equals 0.343 ± 0.005, which agrees closely with the non-classical value. The results of our measurements were compared with data available in the literature. The height dependence of the density of a two-phase sample was investigated in relation to the temperature and time. These experiments made it possible to determine the isothermal compressibility of liquid and vapor phases near the critical point.Paper presented at the Seventeenth European Conference on Thermophysical Properties, September 5–8, 2005, Bratislava, Slovak Republic.     

Synthesis of Optimal Signal Processing for Resonant Gravitational Fast Filtering Antennas from the Analog Prototype

Synthesis is considered for an optimal algorithm for observing single gravitational pulses at the output of a resonant gravitational antenna working with fast filtering by reference to the analog prototype.     

Design and performance of cryogenic enclosures for long duration testing of large samples

We have designed a large helium dewar as part of an experiment to investigate gravitational radiation. Two such dewars have been constructed. Our use requires a nonmagnetic dewar to cool an aluminium antenna of approximately 5000 kg to below helium temperatures and to keep the antenna in a stable low temperature environment for extended time. This requires a low temperature volume of 1.5 m inner diameter and 3.1 m length and a cooling system capable of efficiently removing the room temperature enthalpy of 8.5 × 10⁸ J. Our solution to this problem is of wider application than simply gravity wave detection so we have discussed the design philosophy in some detail. As constructed, the apparatus uses less than 1 l of helium per hour when cold.     

The inverse moment treatment from center of mass depth and four dimensionless shape factors

The inverse moment problem is considered for a homogeneous body with a vertical symmetry axis. One calculates the depth of the center of mass and the four dimensionless shape coefficients independent of the mass and density of the body from the linear and angular radii in models. __________ Translated from Izmeritel’naya Tekhnika, No. 2, pp. 10–14, February, 2008.     

Coincidences between output signal excursions for cryogenic and uncooled gravitational antennas

A statistical analysis is presented of coincidences between the output signals of the cryogenic gravitational antennas Explorer (CERN, Switzerland), and Nautilus (Frascati, Italy), and the uncooled gravitational antenna Ulitka (Shternberg State Astronomical Institute and Moscow University). The purpose has been to check for a geophysical origin for the anomalous correlation registered between the cryogenic detectors at the instant when the direction pattern diagram intersects the plane of the galactic disk. The results do not confirm the geophysical hypothesis and indicate an astrophysical origin.Translated from Izmeritelnaya Tekhnika, No. 10, pp. 3–6, October, 2004.     

Observing and recognizing complicated gravitational signals

An optimal filter receiver is considered for observing and distinguishing quasideterministic gravitational-wave signals against a background of wide-band gaussian noise under conditions of a priori insufficiency. It is shown that optimal input combination of long-baseline laser-interferometer gravitational antennas should lead to a reduction in the probability of erroneous decision. Translated from Izmeritel’naya Tekhnika, No. 12, pp. 3–5, December, 2008.     

Calculating the gravitational constant with the attracting masses on the balance equilibration line

Calculations on the gravitational constant are considered when the attracting masses lie on the line of equilibrium of the torsion balance by the use of a differential equation of motion and an analytic formula containing the fourth power of the oscillation amplitude. Two independent calculations assist in eliminating possible sources of systematic error and enable one to test the correctness of all the assumptions made in the realization.Translated from Izmeritelnaya Tekhnika, No. 10, pp. 7–9, October, 2004.     

Frequency of an Anharmonic Oscillator with Nonlinear Terms of Seventh Order

Calculations are presented on the period of anharmonic oscillations, which incorporate terms up to the seventh order. The example of a mathematical pendulum is used to show that numerical calculations agree with data from other sources. The high-order terms extend the amplitude range for the oscillations for which one can calculate the gravitational constant from analytical formulas. __________ Translated from Izmeritel'naya Tekhnika, No. 9, pp. 11–13, September, 2005.     

The Fundamental Physical Constants,the Gravitational Constant,and the See Space Experiment Project

The paper discusses the fundamental physical constants, the classification of them, the number of them, the definition accuracy, and the relationships to fundamental physical theories (interactions). Basic concepts are presented on gravitational relativistic metrology related to precision space-time measurements. The main attention is given to Newton’s gravitational constant G as regards the measurement of the absolute value and the possible variations in time and space as predicted by interaction union theories. Principles are presented for a proposed space experiment to measure G and its variations, whose implementation will enable one to improve on current data from appropriate laboratory experiments on Earth by 2–3 orders of magnitude.__________Translated from Izmeritel’naya Tekhnika, No. 6, pp. 3–10, June, 2005.     

Sampling the output signal from a resonant gravitational antenna with fast filtering

The scope for coherent digital processing is considered for the narrow-band random process at the output of a resonant gravitational antenna operating with fast filtering and low-frequency sampling. __________ Translated from Izmeritel’naya Tekhnika, No. 7, pp. 7–10, July, 2007.     

A two-channel circuit for protecting a resonant gravitational antenna from correlated non-Gaussian interference

A modernized circuit with a noninertial nonlinear element, a whitening filter and a matched filter, connected in series-parallel, for suppressing correlated non-Gaussian interference at the output of a cryogenic resonant gravitational antenna is considered. The algorithm is based on the use of optimum processing of vector signals. __________ Translated from Metrologiya, No. 5, pp. 3–9, May, 2008.     

A new scheme for processing output data from resonant gravitational antennas

A new scheme is proposed for measuring the noise parameters in the primary processing of the output signal from a resonant gravitational antenna working with fast filtration. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 19–22, September, 2008.