... We describe image compression based on the pyramidal median transform, introduced as an alternative to the use of a wavelet transform. The use of a multiresolution support allows ``protection'' of astronomical objects in the image. ... We describe an approach to astronomical image compression through noise removal. ... We begin by explaining why transforms other than the wavelet transform are important for astronomical image compression. ... Negative Values. ... The image dimensions were . ...

Next: Splitting and Imaging Up: Primary Beams and Mosaicing Previous: Some Additional Tools . The individual approach images, deconvolves, self-calibrates and restores each pointing separately. ... With the `individual approach', it is possible to deconvolve sources (and thus eliminate their sidelobes - which is the important issue) beyond the limit where Miriad 's primary beam model gives up. ... Splitting and Imaging . Deconvolution, Restoration and Self-Calibration . Image Combination . ...

... 8, ``Celestial Mechanics'', 2002 Determination of preliminary orbits including perturbations V. A. Shefer Research Institute of Applied Mathematics and Mechanics, Tomsk State University, Tomsk, Russia On the basis of the theory of intermediate orbits developed earlier by the au­ thor [1], a new approach to the solution of the problem of preliminary orbit determination is suggested. This approach enables to take into account the main perturbations in celestial body motion. ...

LIGHT SCATTERING BY MULTI-LAYERED PARTICLES WITH THE AXIAL SYMMETRY V.G. Farafonov St.Petersburg State University of aerocosmic instrumentation, St.Petersburg, Russia Abstract A new recursive algorithm of solution of the problem of scattering of an arbitrary polarized plane wave by multi-layered dielectric particles with the axial symmetry is constructed. ... The size of truncated? systems for multi-layered particles coincides with that of analogical homogeneous particles. ...

Next: M.D. Smith, Research Astronomer Up: W.M. Napier, Emeritus Honorary Previous: W.M. Napier, Emeritus Honorary . Recent years have seen a downgrading of the threat assessment due to impacts from comets and asteroids. ... Bill Napier, however, has been using new approaches to the problem and finds that the celestial hazard due to impacts may be a factor 5 higher these estimates. ... These bodies may constitute the dominant impact hazard in the 100,000 megaton range. ...

... Archives . ... They find yearly modulation in their detected scintillation rate that matches what you would expect if the Earth were rushing through Galactic Dark Matter as it goes around the Sun. ... Significant! ... Certainly, at 8-sigma, it is easy to accept that there is modulation. ... Astronomers in general are extremely suspicious of any yearly modulations, as we have learnt from hard experience that it is an extremely common source of systematic error. ... Chandra Blog . ...

... Learning set is formed on basis of the Taken' algorithm. ... For 10, 100, 200, 300 day forecast the time lag was correspondingly = 10, = 100, = 200, = 300. ... For every forecast (10, 100, 200, 300 days) ANN started k = 10 times. ... On figure, 1 it is shown the MAE and RMS statistics for 10-, 200- and 300-day forecast for Xp : M AE = 1 n i=n |f orecastav erag ei - realv aluei |, ... i=1 139 RMS 300 MAE 300 RMS 200 RMS 10 MAE 10 MAE 200 Figure 1: 10, 200, 300 day statistics for Xp forecast. ...