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Next: A New Entropy Measure Based on Multiple Resolution and Noise Modeling . ... The entropy measurement has been proposed for image restoration several years ago in astronomy. ... The multiscale entropy has the advantage to introduce a noise modeling, and the concept of information at different level of resolution. ... We show in this paper that it can also be used for background fluctuations analysis. ... Five simulated images were created by adding 400, 200, 100, 50, 0 sources to a noisy image. ...

instr> Quality Control: . Image flats . ... noise parameters | ... linearity, gain . ... While the ordinary, daily fibre flats mainly measure fibre characteristics, the image flats are exposures of the CCD by the flat field lamp without the fibre system. ... Two kinds of small-scale fluctuations exist in any raw frame: photon noise, and fixed-pattern (gain) noise (the third source, read noise, is negligible here). ... The penalty to pay is added photon noise, inherent in the image flats. ...

... Image Quality of the VLT . Total Optical Control . First light for the ESO VLT unit telescope 1 occurred during the workshop. ... The image shown (Figure 1 ) here was obtained with the VLT on May 16, 1998, in red light (R band), i.e. while the mirror was still uncoated. ... In this diagram (FIgure 2), the measured image quality of the VLT UT1 astronomical images is plotted versus the ``seeing", as measured by the Seeing Monitor, a small telescope also located on top of the Paranal Mountain. ...

Astronomy Picture of the Day . ... Recognizable bright nebulae include NGC 7000 ( North America Nebula ), and IC 5070 ( Pelican Nebula ) at the upper left with IC 1318 ( Butterfly Nebula ) and NGC 6888 ( Crescent Nebula ) at lower right -- but others can be found throughout the wide field. ... NASA Web Site Statements, Warnings, and Disclaimers . ... Publications with keywords: Cygnus - emission nebula . Publications with words: Cygnus - emission nebula . ... IC 1396: Emission Nebula in Cepheus . ...

... 53 љ int getMaxLevel( void ) const { return maxLevel;} . ... 59 љ typedef void (VisitFunc)( int lev, int index, . ... 71 љ int getZoneNumberForPoint ( const Vec3f &v, int searchLevel) const ; . ... 74 љ void getTriangleCorners ( int lev, int index, Vec3f & c0, Vec3f & c1, Vec3f & c2) const ; . ... 77 љ int getPartnerTriangle ( int lev, int index) const ; . ... 105 љ const Vec3f & getTriangleCorner( int lev, int index, int cornerNumber) const ; . 106 љ void initTriangle( int lev, int index, . ...

... In laboratory the design and a manufacturing techniques mirror aspherical optics are developed ("fokon", ellipsoid, aspherical mirror).Such optical elements are made of widespread aluminium alloys on the standard equipment without use diamond turning. ... Using: optical blocks of not image optical devices for transitions, collimation, focus (concentration) radiations in a wide spectral range from UV to IR. Focusing and collimation of light; . ... circle aperture/ring aperture; . ... Back Forward . ...

Surface-layer turbulence measurements with lunar scintillometer Idea of the method Hardware & software Campaigns & results New horizons Andrei Tokovinin NOAO/CTIO Kislovodsk Oct. 2010 1 Turbulence measurement from scintillation of extended sources Moon's angular diameter =0.5 deg Correlated scintillation for b > z z=10m b=0.1m z=100m b=1m z=10km b=100m BI(b) = W(b,z) Cn2(z)dz Weighting functions zW(z) for b=0...0.4m and d=1cm 2 Kislovodsk Oct. ... 2010 12 Paranal: October 14, 2008 Kislovodsk Oct. ...

Please enter the lightcurve file name and period search parameters: . Lightcurve file: . ... Apply the Heliocentric correction and convert all dates to Terrestrial Time (TT)? ... Phase range for plots: -0.5 to 1.0 0.0 to 2.0 0.0 to 1.0 . ... Also, the Heliocentric correction cannot be applied to such lightcurves. ... Two period search methods are currently implemented. ... This period search service is also available at the mirror sites: Mirror 1 , Mirror 2 , Mirror 3 , Mirror 4 . ...