... We present the algorithm and implementation details for the robust, realtime bandpass removal and calibration routine developed for the HI Parkes All Sky Survey project. ... Traditionally, the bandpass that is present in single-dish 21 cm spectra is removed by observing in a ``signal-reference'' mode. ... The robust bandpass removal algorithm implemented for the HIPASS Project successfully produces calibrated HI emission line spectra for most of the survey data. ...

... Instead, a statistical estimate of the bandpass at the position and time that a particular spectrum---the target spectrum---was acquired is made from a set of earlier and later spectra observed by the same beam---these are the reference spectra. ... I b;p;c is a 1024­ channel flux density spectrum. For a given beam and polarization pair, the target spectrum is I b;p;c target , and the reference spectra, R, are a set of spectra which can be used to estimate the bandpass for the target spectrum. ...

... Robust Bandpass Removal Traditionally, the bandpass that is present in single­dish 21 cm spectra is re­ moved by observing in a ``signal­reference'' mode. ... Instead, a statistical estimate of the bandpass at the position and time that a particular spectrum---the target spectrum---was acquired is made from a set of earlier and later spectra observed by the same beam---these are the reference spectra. ... I b,p,c is a 1024­ channel flux density spectrum. ... References Barnes, D. G. 1998, this...

ALMA | ... In this section, we explain why we need to correct phase fluctuations and ALMA's strategy to do this. Rapid fluctuations will be corrected with water vapour radiometers (WVRs). The Cavendish Astrophysics Group was also a leading contributor to the ALMA prototype WVRs, which were put through their paces in tests at the Submillimeter Array (SMA). ... The Cavendish Astrophysics Group in partnership with the Onsala Space Observatory built two prototype WVRs for the ALMA project. ...

... The procedure of radiometer signal integration can be considered as a sort of reducing dimension of the initial sampling space, where the samples are the result of analog-to-digital conversion. ... The probability distribution of the signal and spikes is completely known. ... The quality of the considered algorithm could be also illustrated by Figure 2 . ... One could see the considered adaptive algorithm is preferable even by low degree of compression, because all spikes have been depressed. ...

RFI SUBTRACTION WITH A REFERENCE HORN: APPLICATION TO PULSARS AND VLBI F. H. Briggs (1) , M. J. Kesteven (2) (1) Kapteyn Astronomical Institute, Postbus 800, 9700AV Groningen, The Netherlands, fbriggs@astro.rug.nl (2) CSIRO Australia Telescope National Facility, P.O. Box 76, Epping, NSW 1710, Australia, mkesteve@atnf.csiro.au ABSTRACT Cross correlation of an RFI reference signal with the corrupted radio astronomy data ... Fig. ... PHASE A B C D 1 2 1 2 1 2 1 2 Fig. ...

... A good introduction to optimization theory and a description of the the modern minimization techniques can be found in Gill, Murray and Wright [1]. Bard [2] deals with the particular problem of parameter estimation; chapters concerning the different estimators and their properties, and the interpretation of the estimates are remarkable. ... 1] Gill P.E., Murray W and Wright M.H. Practical Optimization. ... 3] Gill P.E., Murray W. Algorithms for the solution of non-linear least squares problems. ...

... This project was my personal idea quite some time ago: to port XFree86 , the free and optimized X11R6 implementation to OS/2. ... XFree86/OS2 is now available as a public version 3.3.6, which does not expire and for which full source code is available. ... x.physics.usyd.edu.au Please send a mail to me with a complete URL if you have set up a ftp server or a mirror for XFree86/OS2. ... Available ported software . ... I'll still be available as the mediator between XFree86/OS2 and general XFree86. ...

... All the parameters provided in this database have been obtained using the the MIRIAD ( Sault et al. 1995 ) task MBSPECT . MBSPECT makes a spectrum of the velocity (or frequency) axis of a cube. The spectrum is beam-weighted, over the width specified, for the other image axes. ... Robust parameters are calculated by using an algorithm which minimises the mean absolute deviation of the flux-weighted velocities. mask= This specifies the x-axis ranges to be excluded from any continuum fit. ...

. Next: To display a particular Up: *display, xdisplay, xexamine* - Previous: To both compress and . tv> xdisplay ``xdata$rp110590.qp[block=30, pi=7:40]'' # will display only data # from pi channels 7-40. PSPC PI channels available are 1:256, use of 7:240 only is recommended . rsdc@cfa.harvard.edu . 1998-06-10

... This effect is visible in Figure 4.3 which shows a logarithmic stretch of the image resulting from a 100s exposure on a star of V magnitude 2.6 through filter F502N in the PC. Extreme overexposure of the Loral CCDs is not believed to cause any permanent effects, and therefore the WFPC2 does not have a bright object limit. ... Several other artifacts that are common in saturated stellar images are also obvious in Figure 4.3 . ... Figure 4.3: Saturated Stellar Image Showing Horizontal Smearing. ...

... The next fragment computes the backscal and frac_exp statistics from the accumulated exposure, which is just the sum over all exposure map pixels that lie within the spatial selection region at the given channel. ... IF ( mode == HTR ) fg.backscal = background distribution integrated over EnergySourceRegion bg.backscal = background distribution integrated over EnergyBackgroundRegion normalizer = $rebin * extent( SpatialSourceRegion ) * fullExposure frac_exp = normalizer ? ...

... English (Australia) . ... Science User Portal . ... ESO, the European Southern Observatory . ... Travel and Contacts . Travel to ESO Headquarters . ... Travel to Paranal . ... ESO Acronyms . ... Survey Telescopes . ... ESO Science Newsletter . ... FORS1 and FORS2 . ... ESO 3.6-metre telescope . ... MPG/ESO 2.2-metre telescope . ... The FORS team from G†ґttingen, Heidelberg and Munich (Germany) started unpacking and re-integration of instrument sections next day in the Auxiliary Telescope Hall . ...

... Flight 1) 2) 3) Flight 1) 2) 3) model FM1 has the following parts: LNA MY-18, serial number PN 01-0252, factory number FM1; receiver box KRT-18, serial number PN 17660-01, factory number FM-001; DC-DC converters IVEP1 and IVEP2, factory number 05. model FM2 has the following parts: LNA MY-18, serial number PN 01-0252, factory number FM2; Receiver box KRT-18 serial number PN 17660-01, factory number FM-002; DC-DC converters IVEP1 and IVEP2 factory number 06. ... See Appendix 1. ... 2003. ... 2004 . ...

... Torgashina, Gert de Lange, Leo de Jongb, Pavel A Yagoubovb a The Kotel'nikov Institute of Radio Engineering and Electronics, Moscow, Russia b SRON Netherlands Institute for Space Research, Groningen, the Netherlands Abstract--A Superconducting Integrated Receiver (SIR) developed for balloon borne instrument TELIS covers frequency range 450-650 GHz. The DSB noise temperature was measured as low as 120 K. The SIR application for high resolution spectroscopy of breathed out air has been proven. ...

Some recent results ( see ) attracted the attentions of astronomers working on field which could benefits from photon counting techniques with high speed and spatial resolutions as adaptive optics. ... Fasti has been designed to be fast and largerly configurable. ... The data rate attined in the best case (30 Mhz), give no impossible load to the digital acquisition in the photon counting mode, since data are 1 bit only, they can be parallelized, giving a maximum speed of about 940.000 32 bit word/sec. ...

... Wavelength Calibration . ... 30s wavecal plot . 30s flatfield plot . ... HeNeAr 4400 . B rQrtz 4400 . ... HeNeAr 4500 . ... BrQrtz 4200 . BrQrtz 4500 . ... These figures in the above table show the number of counts received from each of the lamps in a 30 second exposure with the 1.5 arcsec slit. ... Users have the option of taking calibration lamp data at the rotator angle of each object, but in many cases, it should be possible to measure the shift using observations of night sky lines. ...

... Exposure Time Calculator (ETC) . Survey processing . ... VISTA is a 4-m class wide field survey telescope for the southern hemisphere, equipped with a near infrared camera (1.65 degree diameter field of view at VISTA's nominal pixel size) containing 67 million pixels of mean size 0.34 arcsec and available broad band filters at Z,Y,J,H,K s and a narrow band filter at 1.18 micron. A wide field visible camera, if constructed, could also be used on VISTA. ... Tile . ... ESO VISTA Public Surveys . ...

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. ...

Image analysis of the VLBI experiment INTAS99.4 . PI: I. Molotov (GAO, Russia) . Analyst: A. Pushkarev (GAO, Russia; CrAO, Ukraine) . ... Frequency: 1.66 GHz . ... Antennas and their characteristics at 1.66 GHz . ... Bear Lakes (Russia) . ... Svetloe (Russia) . ... Pushchino (Russia) . ... CALIBRATION . Amplitude Calibration . Phase Calibration . ... 0420-014 . ... Quasar . ... 0420-014.gif . ... 0420+022 . ... 0420+022.gif . ... 0552+398 . ... 1308+326 . ... 1345+125 . ... 1803+784 . ...