Next: Some theory Up: userhtml Previous: Calibration . By many measures, the ATCA 3-mm observing band is a completely different domain to the other ATCA bands. ... Not surprisingly many aspects of the data reduction are also different. This chapter reviews the theory behind some of the differences, and then considers a practical approach to calibration. ... Antenna gain considerations and flux calibration . Instrumental phase . Atmospheric phase and phase calibration considerations . ...

... E1 Apertures Kailash C. Sahu March 9, 2004 ABSTRACT A calibration program was carried out to determine the spectroscopic LSFs at the pseudo-aperture locations (E1 apertures) for the first order CCD modes. Observations were taken with the narrowest 52X0.05 acrsec slit to minimize the effect of the aperture on the determination of the LSFs. ... The dotted lines are the LSFs obtained at the nominal aperture locations and the solid lines are the LSFs obtained at the pseudo aperture locations. ...

... Let us first find out which way -- rise in spectral resolution with some loss in the S/N ratio or increase in the S/N ratio with a fixed spectral resolution -- is better for the purpose of reduction of equivalent width determination errors. ... N -- number of counts for 1 ? ... line equivalent width, . ... Thus if the spectral resolution is managed to be increased (i.e. to decrease )without loss in the number of counts falling at 1 ?, the equivalent width measurement error is then proportional to . ...

... In order to compare the number of different evolutionary stages obtained and X-ray luminosity of the chosen X-ray sources with the observed galactic values we use the sum of C/O+O/C , where C and O are the calculated and observed values of a given binary type, respectively. If we make comparison for a number of different binary species (for example, we compare the number of CV, number of X-ray pulsars,   total X-ray luminosity of LMXB, etc.), we write this criterion in the form: . ...

CHIANTI - an atomic database for emission lines. ... K.P.Dere, E.Landi, H.E.Mason, B.C.Monsignori-Fossi, P.R.Young, 1997, A , 125, 149 . Article: Available from ADS . The Arcetri Spectral Code for thin plasmas . E.Landi M.Landini 1998, A , 133, 1 . ... E.Landi, M.Landini K.P.Dere, P.R.Young, H.E.Mason, 1999, A , 135, 339 . ... K.P.Dere, E.Landi, P.R.Young, G.Del Zanna, 2001, ApJS, 134, 331 . ... G.Del Zanna, B.J.I.Bromage, E.Landi, M.Landini, 2001, A , 379, 708 . ...

Next: Results of observations Up: Observations and data reduction Previous: IPCS observations and data . The observations in 1996 were carried out with a new CCD-detector in two different set-ups. In February 1996 we used B0 grating (300 grooves/mm) with the wavelength coverage of 3600 - 7000? and a dispersion of 5.2 ?/pixel and B1 grating (600 grooves/mm) with the interval 3600 - 5400? and a dispersion of 2.6 ?/pixel. ... with the dispersion 2.3 ?/pixel and grating B1. ...

Atmospheric influence on the different radio-engineering system functioning . ESTIMATION OF ATMOSPHERIC OPTICAL CHARACTERISTICS AND REMOTELY SANSED IMAGE CORRECTION . ... Direct transmittance estimation results for 12 channels of the spectrometer CHRIS. ... We have managed to develop a direct method of estimating the discrete Normalized Atmospheric Point Spread Function (NAPSF) from available images alone, not using any external sources of information about the atmosphere. ... IRE RAS 1996-20 11 ...

... Second, the observatory can control the configuration, test data analysis procedures, and provide calibration solutions with the help of instrument models. This paper presents the VLT object-oriented framework for the development of ETCs (Exposure Time Calculators) and data simulators. ... Instrument simulations are being developed for the purpose of predictive calibration, instrument configuration control, and evaluation of data analysis procedures. ...

Next: Results & Discussion Up: Coronal Hole Diagnostics out Previous: Introduction . ... The dates of the observations discussed here, their locations, pointing, slit sizes and exposure times are given in BTDW. ... Line fits are given by the dotted line. ... An estimation of the errors in the derived parameters was obtained using the GA-derived parameters as an input for a ``classical'' IDL-CURVEFIT procedure (Peter, 1999; Peter & Judge, 1999). ...

Crater Gassendi . ... I made this drawing was made on the 26th of november 2001. If you compare this one with the previous drawing of Gassendi (below) the differences are clear. ... This drawing was made on the 28th of september 2001. After nearly a full month without observations I had a one hour gap between the thicker clouds. ... This drawing was made on the 29th of august 2001. ... This drawing was made on the 27th of august 2001. ... This drawing was made on the 25th of august 2001. ...

This thread illustrates how to evaluate if your RGS observation is affected by pile-up; if so, how to deal with it in some special cases; and how to prevent it occurring. ... Pile-up will cause two coincident first order . ... Thus, pile-up may differ between RGS1 and RGS2 and may abruptly vary between CCD locations due to the nominal event pattern distribution variations over the detectors. ... Migration of photons from 1st to 2nd order (or from 2nd order to 3rd order) . ...

Different backends are supported by CIMA depending on the selected receiver and observation type (spectral line or pulsar). CIMA has traditionally supported two backends: the interim correlator for spectral line single-pixel receiver observations and the WAPPs for any kind of observation. The WAPPs behave quite differently in spectral line and in pulsar mode, with the differences being so big that the observer has to select which type of obsercvation already at start-up of CIMA. ...

... 2013 May 14 . Galaxy Collisions: Simulation vs Observations . Images Credit: NASA , ESA ; Visualization: Frank Summers ( STScI ); Simulation: Chris Mihos ( CWRU ) Lars Hernquist ( Harvard ). Explanation: What happens when two galaxies collide? Although it may take over a billion years, such titanic clashes are quite common. ... Pictured above is a computer simulation of two large spiral galaxies colliding , interspersed with real still images taken by the Hubble Space Telescope . ...

... the time of observation . ... Observing the Changing Position of the Sun To Establish Cardinal Directions . ... Observations of the Sun's apparent movement across the sky and its pattern of rising and setting in the east and west horizon helped to establish the cardinal directions. ... The final stage of the Sun's return was marked by the observation that the Sun had reached its highest altitude when the full width of your mitted hand could fill the gap between the Sun and the horizon. ...

RTT150 . ... This search system is designed for generating the necessary information on series of pointings (observations of each source consist of sets of exposures with different filters and sometimes with different exposure times) for observed sources. Search results appear at the separate page as a table with the following data: . DATE - real (not evening!) observations date (in YYYY-MM-DD format); . ... Bin - minimal CCD binning mode (may vary during the observations); . ...

... ESO, the European Southern Observatory . ... ESO Acronyms . ... Survey Telescopes . ... Star Clusters . ... Stars@ESO . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... Demonstrates in a schematic way, how the images of two stars of different angular size (left) will look like, with a single telescope (middle) and with an interferometer like the VLTI (right). Whereas there is little difference with one telescope, the fringe patterns at the interferometer are quite different. ...

... ME AND MY SCHOOL . SOURCES . THE CHART OF THE DIFFERENCES IN THE SPELLING OF SOME WORDS CONNECTED WITH SCHOOL AND EDUCATIONAL SYSTEM IN BRITAIN AMERICA. ... РАЗЛИЧНЫЕ СТРАНЫ ИМЕЮТ РАЗЛИЧНЫЕ СИСТЕМЫ ОБРАЗОВАНИЯ, НАПРИМЕР ВЕЛИКОБРИТАНИЯ ИЛИ СОЕДИНЕННЫЕ ШТАТЫ. ... ОБО МНЕ И МОЕЙ ШКОЛЕ(ME AND MY SCHOOL), . ... А ТАКЖЕ ВАМ ПРЕДЛАГАЕТСЯ ТАБЛИЦА РАЗЛИЧИЙ В НАПИСАНИИ И ПРОИЗНОШЕНИИ СЛОВ СВЯЗАННЫХ С ОБРАЗОВАТЕЛЬНОЙ СИСТЕМОЙ В США(AMERICAN ENGLISH)И ВЕЛИКОБРИТАНИИ(BRITISH ENGLISH)-THE CHART . ...

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. ...

Peremennye Zvezdy ( Variable Stars ) 35 , No. ... We present the results of our new observations of QS Draconis, a recently discovered double-mode high-amplitude Scuti variable, HADS(B) type. ... Our CCD observations in the Johnson bands were performed at the Tien Shan Astronomical Observatory of the V.G. Fesenkov Astrophysical Institute, at the altitude of 2750 m above the sea level. ... The finding chart (Fig. 1) identifies the variable star, comparison star, and check star. ... Fig. ...

Next: Filtering ROSAT HRI data Up: ROSAT HRI Recipes Previous: Correlating Spectral Data with . Although the spatial variation of the quantum efficiency across the HRI is nominally within 10% for most of the detector, occasionally it may be desirable to flat-field a map with preflight calibration measurements. ... Store the new gain map image using ``blink" in SaoImage. ... The quantum efficiency correction (QEC) is the inverse of the intensity determined from the QE map at the source position. ...