Phase Retrieval Measurements of Antenna Surfaces Using Astronomical Sources Bojan Nikolic, John Richer, Richard Hills Mullard Radio Astronomy Observatory, Cavendish Laboratory, Cambridge, U.K. Abstract We present a novel technique for accurate measurement of the largescale errors in an antenna surface using astronomical sources and detectors. Out-of-focus images of compact astronomical sources contain a wealth of information about the telescope optics. ...

On Systematic Differences in Individual Solutions and IERS Products Zinovy Malkin Institute of Applied Astronomy RAS, St. Petersburg, Russia 1 Present status Proper determination, modelling, and accounting for systematic differences between contributed series is of the great importance in compilation of the IERS products. ... Possible sources of systematic differences are: · Different reference systems (e.g. TRF, CRF, geopotential, time scale). ... 87 IERS Technical Note No. ...

... Archives . ... If you do not mind the time predictor, it is hard to believe that this is a light curve, time dependent data. ... It?s hard to say this data set is designed for time series analysis apart from the complication in statistical inference due to measurement errors. How to design the statistical study with measurement errors, huge gaps in time, and unequal time intervals is complex and unexplored. ... The following is R output without measurement errors. ... Chandra Blog . ...

Scale-heights of the Galactic disk subsytems with different ages and metallicities . V.Marsakov & Yu. ... It is based on the fact, that all stars cross the disk plane several times during their Galactic orbital period. ... We have used our representative sample of nearby disk F2-G2 stars Marsakov & Shevelev (1995) in which fundamental stellar parameters was determined on the basis of published date on uvby-photometry, proper motion and radial velocities. ... Marsakov V.A., Shevelev Yu.G. Bull. ...

... 2007 June 2 . 3D Full Moon . ... Explanation: Get out your red/blue glasses and check out this satisfying stereo anaglyph of the Full Moon. ... Regardless of your preferred technique for stereo viewing , the 3D effect comes from combining pictures of the same scene taken at different angles -- mimicking the slightly different perspective of each eye. Perhaps surprisingly for Earthdwellers , getting two pictures of the Full Moon from different angles only requires a little patience. ...

Russian SHAREABLE DATA CENTER Institute of Solar-Terrestial Physics SB RAS . ... The algorithm and appropriate program for decametric radiosignal propagation conditions prediction for paths from 500 to 9000 km have been developed at ISTP SB on the basis of normal wave method (AltyntsevaB.I,Iliyin N.V., Kurkin V.I. and others //Decameters channel simulation on the base of normal wave method . ... Solar activity indices are chosen automatically from the prediction date from the database . ...

... 13, Moscow 119992, Russian Federation, e-mail: busarev@sai.msu.ru; 2 Research Institute Crimean Astrophysical Observatory, p/o Nauchnyi, Crimea 334413, Ukraine, e-mail: prok@crao.crimea.ua Summary: We propose a combined method of astronomical investigations of small or distant planets incorporating registration of a set of integral spectra of an object and their frequency analysis. ... An application of the method is shown on example of asteroid 21 Lutetia. ... 6] Busarev V. V. (2002), Solar Sys. ...

REPORT ON PIERRE DELIGNE FELLOWSHIP, 2010 SERGEY OBLEZIN During 2010 I have been working on developing a representation theory approach to mirror symmetry and quantum cohomology of homogeneous spaces, associated to Lie groups of classical type. According to Givental the glN -Whittaker functions, being solutions to the quantum cohomology D-module QH (FlN ) of the complete flag variety FlN = GLN (C)/B , describe the corresponding equivariant Gromov-Witten invariants of FlN . ... J. (2010). ...

... The SDSS 2.5-m primary mirror is supported in a manner similar to the Apache Point Observatory 3.5-m telescope primary. ... The axial support is provided by 48 air pistons. The pistons have the same diameter thereby applying equal forces with the same air pressure. ... Each group supports a 120њ sector of the mirror. ... Figure 1: CAD drawing showing the 2.5-m primary mirror and the locations of actuators (green circles) These actuators apply forces (10*cos2 N) to correct astigmatism. ...

We model the spectral chanages of late oxygen-rich Miras observed in different pulsation phases. From a combination of variable near-IR spectra and UKIRT spectrophotometry of the 9.7 \mu m silicate dust emission feature in different phases we study the influence of the changing atmospherical circumstances on the conditions in the circumstellar dust shell. ... A comparision with the modelling results for another long period Mira U Ori is also provided. ...

Download Izmccd (~2.7 MB). ... a) a choice of the best mode of measurements of stars and objects ("Properties/Measurement"), . b) a choice of reference stars. ... 1) necessity of presence on an image of a plenty of stars (we recommend to apply this mode, if on the frame of reference stars is more 100) . ... Sx and Sy depend from residuals at all reference stars (reference stars are marked by blue color). ... These residuals are the image of the star a minus function of a profile for each pixel. ...

... During the analysis of the surveys carried out on RATAN-600, it was found that almost one fifth of the detected sources shows significant radio flux variations. ... We used the data from "Cold" radio surveys carried out with RATAN-600 in 1980-1994 to search for radio sources with significant flux variability. ... On possibility of detection of variable sources using the data of Cold surveys carried out on RATAN-600. ... Detection of Variable Sources Using the Data of "Cold" Surveys. ...

... Clearing the library. Note the different flooтАж . Sidebar Left . Sidebar Top . ... Title: Clearing the library. Note the different floor levels. There were at least 4 different levels of underfloor in the library. Description: NOTE: All images and movies are copyright and must not be reproduced or mirrored in any form without written permission. ... NOTE: All images and movies are copyright and must not be reproduced or mirrored in any form without written permission. ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

To main of Laboratory . The research work and design of optical and optical-electronic devices are carries out by laboratory staff: . ... Lens: . ... In the layout 1 prism systems perform functions of dispersive element, corrector of aberrations, optical reducer. ... Spectral range 200 - 400 nm; . ... Back Forward . ... The main corrector's function are compensation of field aberrations of the main spherical mirror of a telescope (diameter of 600 mm, f'=1200 mm) and increase aperture ratio. ...

... SiD workshop, Fermilab, April 9-11 2007 April 9, 2007 Nick Sinev, SiD design Workshop, Fermilab 1 Topics 1. ... What and how was simulated What and was One column clusters effects Accepted background density Hit reconstruction efficiency Hit efficiency How to improve efficiency Conclusions April 9, 2007 Nick Sinev, SiD design Workshop, Fermilab 2 What is this April 9, 2007 Nick Sinev, SiD design Workshop, Fermilab 3 Marty's idea Shift charge in neighboring columns in opposite directions. ...

... Contact A Problem of an estimation of accuracy of the asteroid CCD observations . The Minor Planet Center supported by the Interntional Astronomical Union is the main office for keeping observational data of the small Solar System bodies and their investigations. ... At Pulkovo Observatory we are estimating an accuracy of the CCD asteroid observations obtained by amateurs and professional astronomers all over the World using the MPC database. ...

... Science . User Portal . ... Science Users Information > Data Handling and Products > Data Reduction FAQ > Why do the flats in my data have different exposure times and how do I know which ones to use? ... Science Users Information . ... Observing with ESO Telescopes . ... Telescope Time Allocation . ... Science Data Products Forum . ... ESO Data . ... ESO Data Access Policy . ... ESO Science Newsletter . ... The exposure times of the flat fields depends on slit width and readout mode. ...

home education > activities . ... Quick math activity that asks students to calculate scale models of a binary star system with a black hole in it. [h] . ... Students use a radiometer and a light bulb with a dimmer switch to make connections between the temperature, color, and radiation output of a star. ... This demonstration, similar to the above, from the Exploratorium Snack-book of science activities, lets students demonstrate how molecules scatter light and change the colors of the beam. [m,h] . ...

. There are several different shells available for Unix; the most popular are described here. You can use any one of these shells if they are available on your system. And you can switch between the different shells once you have found out if they are available. Bourne shell (sh) . C shell (csh) . TC shell (tcsh) . Korn shell (ksh) . Bourne Again SHell (bash) .