... Since image restoration algorithms are highly sensitive to the accuracy of the calculated PSF, a significant portion of our research effort is devoted to accurately modeling the PSF which is a highly non-linear problem. Our approach is based on analytical modeling of the wavefront phase using Zernike polynomials. ... In the Fourier domain, we scale the phase map by an observed PSF to more accurately account for the HST/FOC combination. ... The final result is an improved estimate of the phase map. ...

The approaches mentioned in the section title belong to one family which is called in Newton's book [ 56 ] the short waves or high energy approximation (HEA). It means the scattering by soft particles (or potentials) in the case of the wavelengths short in comparison with the particle size (or correspondingly the case of scattering of high energy particles by the potentials). ...

Geomagnetic storms and substorms are a natural hazard similar to hurricanes, floods etc. ... Solar and geomagnetic activity also probably influences the Earth's climate and human health. ... Under southward directed IMF the Earth's magnetosphere is open to input from the solar wind flow. ... Since practical importance of solar wind measurements was recognized, a number of approaches was developed for prediction of the geomagnetic activity basing on the solar wind data. ...

... The cross entropy for this complex image is given by ( 16 ) and ( 17 ). ... Differentiating ( 31 ) with respect to and , we find the gradient of is given by . and upon differentiating once more we find the Hessian (curvature) matrix of has the form . ... and its Hessian matrix reads . ... From ( 16 ) and ( 17 ), we find the components of the gradient vector of the cross entropy are given by . ... Differentiating once more we find the components of the Hessian of the cross entropy to be given by . ...

Next: Imaging - INVERT Up: Primary Beams and Mosaicing Previous: Summary of Imaging Strategies . For the joint approach, the reduction proceeds in a fashion which appears very similar to conventional observations. First a dirty image is formed (with associated point-spread function), and then a deconvolution algorithm is used to `clean' this dirty image. ... Imaging - INVERT . ... Next: Imaging - INVERT Up: Primary Beams and Mosaicing Previous: Summary of Imaging Strategies Miriad manager . ...

... Up: Algorithms . ... Non-linear and non-parametric algorithms for data averaging, smoothing and clipping in the RATAN-600 flexible astronomical data processing system are proposed. Algorithms are based on robust methods and non-linear filters using an iterative approach to smoothing and clipping. ... The history of algorithms, based on the robust methods and non-linear filters using an iterative approach to smoothing and clipping, began twelve years ago in the data reduction at the RATAN-600. ...

The beam pattern and the polarization characteristics . of the radio telescope RATAN-600 . The Mueller matrix elements was computed via formulas [1]: . ... The BP were computed by the aperture method, proceeding from the fild distribution in the aperture of the primary mirror. The components of the main and cross-polarization components of the electric field in the vertical aperture of the primary mirror was computed in Frenel diffraction approximation. ...

... DEPENDENCE OF ORDINARY WAVE ANOMALOUS ABSORPTION ON THE SOUNDING PROBLEM PARAMETERS . ... Transformation of electromagnetic wave into plasma waves plays an important role in different processes taking place in ionospheric plasma. ... According to modern point of view transformation of ordinary wave into plasma waves plays an important role in small-scale random irregularities generation when ionospheric plasma is heated by power radio wave [1,2]. ... Anomalous attenuation. ...

... Meta Index / Home Page / Algorithm . ... SNRMAX =0 TOTAL_SRC_ COUNTS = counts in the input image within the source region corrected for the encircled energy fraction of the source region Loop TEST_RADIUS = 1 to 300 arcseconds EEF = calculate encircled energy fraction for this TEST_RADIUS using the PSF relevant for this Epic camera at the position of the source box for a photon energy of 1.5 keV SRC_COUNTS = TOTAL_SRC_ COUNTS * EEF ...

Do we need various assumptions to get a good FCN? A new multiple layer spectral method Cheng-li HuangMian Zhang Shanghai Astron. ... No FCN ! ... FCN,FCN,FCN.. Multiple layer spectral method (MLSM) + Linear Operator Method (LOM) Finite Element Method (FEM) · · Traditional approach solves one order ellipsoid only. ... Main Idea of FEM Boundary Surface could be described as: Let's consider how to solve the dynamic equation: Traditional Approach: Equivalent Spherical Domain . ...

Algorithm for calculations of the Voigt function . ... алгоритма расчета профиля Фойгта ! ... функция Фойгта ! текст модуля на языке Паскаль (Delphi) для ее вычисления ! ... github.com...dawson.cpp процедура Хумличека для вычисления функции Фойгта ! ... Humlicek 1979 JQSRT v21 p309 ! ... 2005A+A___442___11F 2006 Tepper-Garcia, MNRAS, v369 p2025 ! 2006MNRAS_369_2025T 2007 Letchworth and Benner, JQSRT, v107 p173 ! ... 2009JQSRT_110__376A 2014 Abrarov and Quine, J. Math. ...

... The described algorithm is suitable for measurements of complex images of stars. ... a) the zero-based number of stars in the complex (multicentric) image, . b) set of preliminary coordinates - x i , y i , for all stars, index i is number of a star, . ... i - index of a star in the complex image; . ... These parameters are calculated by a nonlinear method of a least squares.The main output parameters of this algorithm are x i , y i ; where the index i is number of a star in the multicentric image. ...

Weaving together Astronomy+Statistics+Computer Science+Engineering+Intrumentation, far beyond the growing borders . ... Archives . ... A fast Bayesian approach to discrete object detection in astronomical datasets ? ... Algorithms arXiv Astro Bad AstroStat Bayesian CHASC Cross-Cultural Data Processing Fitting Frequentist Galaxies gamma-ray High-Energy Imaging Jargon Job Languages MC MCMC Meta Methods Misc News Nuggets Objects Optical Physics Quotes Spectral Stars Stat Timing Uncertainty X-ray . ...

... We have calculated the binary coalescence rate with time using the ``Scenario Machine'' code, which allows us to simulate evolution of large ensembles of binary stars in an artificial galaxy using a Monte Carlo method (see Lipunov 1992, Lipunov et al 1994, 1995 and references therein). ... The source evolution in a galaxy with given star formation rate is thus calculated as , where is the redshift at the turn-on of star formation, which is the second important parameter of the model. ...

This section is on a higher level than the rest, and is primarily meant for advanced users, who may wonder how orbital motion is actually derived. ... As stated earlier, the motion of a satellite (or of a planet) in its elliptical orbit is given by 3 "orbital elements": . ... 3) The mean anomaly M , an angle growing at a steady rate, increasing by 360 degrees each orbit . ... In polar coordinates ( r,f ) describing the satellite's motion in its orbital plane, f is the polar angle. ... The angles: . ...

Electron Bombarded, Back-Illuminated CCD Sensors . ... EBCCD PERFORMANCE: EBS Gain . ... To the first order, the signal gain in the EBCCD is proportional to the kinetic energy of the photoelectrons prior to their impinging on the CCD back surface. ... To obtain EBS gain in the active material, it is necessary for the photoelectron to enter the pixel from the back surface of the CCD -- away from the gate structures that dissipate the electron energy. ... The EBCCD EBS gain was tested using two methods. ...

Asteroid 2004 MN4 was discovered on the 19th of June 2004 by Roy Tucker, David Tholen and Fabrizio Bernardi of the University of Hawaii Asteroid Survey from Kitt Peak Arizona. ... After a few days it was recognized that it would make several close approaches to Earth in the 21st century. ... These distances were calculated by the Near Earth Object Dynamic Site using data available up to 2005 February, to check for updates go to Near Earth Object Dynamic Site . ... PHA Close Approaches To The Earth . ...

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. The comet of Enke. I. Enke calculated the orbit of this comet. Perhaps tungysky meteorit (1908) was the fragment of its core. The nearest approaching with the Sun will take place in 2004. Perhaps this approaching will be the last because of the small mass of its core. Back .

MODERN APPROACHES TO CALCULATION OF THE PROPERTIES OF MATERIALS FOR ENERGY STORAGE A. Kabanov Samara State University The modern technologies demands to compact and effective rechargeable systems of energy storage. ... In this work we investigated the activation energies of one promising compound ­ Li2CoPO4F using combination of two methods ­ ab-initio and geometrical calculations. ... The nudged elastic band (NEB) method is adopted to find the kinetic energy barrier along diffusion pathways. ...