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. ...

... Previous: Generalized Linear Multi-Frequency Imaging in VLBI . ... At Astronomical Observatory of Valencia University (OAUV), CCD observations of asteroids and big planets satellites are obtained since 2001 with a big format camera and several telescopes. ... Software for comparison of single and overlapped CCD fields obtained at different epochs has been developed. ... After images measurement in CCD field, catalogue stars are identified and adjusted with images. ...

SAI 175 anniversary . ... Moscow University . Search for in SAI Moscow University Search for in Russian astronomical resources . ... SAI Astronomical Databases . ... Browse SAI Software archive(ftp.sai.msu.su) . ASTRONET.RU - Russian Astronomical Network (available in translit also) . ... SAI Supernovae Research Group . ... Department of the Galaxy and Variable Stars (in Russian) . Sternberg Astronomical Institute Seminars . ... All-Russian Astronomical Olympiad (in Russian) . ...

... Donate to Support Science Literacy . ... 2016 Annual Awards . The ASP is accepting nominations for the organizationтАЩs national annual awards which recognize special achievements in astronomy research, technology, education, and public outreach. ... Shop the AstroShop . ... The Astronomical Society of the Pacific (ASP) is accepting nominations for the organizationтАЩs national annual awards which recognize special achievements in astronomy research, technology, education, and public outreach.. ...

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. ...

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 . ...

... The Science Operation Department is composed of Astronomers, Telescope Instruments Operators(TIOs) and Data Handling Administrators(DHAs). ... Astronomers have proposed several methods to quantitatively measure the amount of turbulence above the telescope, which the most common ones is Differential Image Motion Monitor (DIMM). In optical testing, the Hartmann test is the common method to test the quality of optical components. ... Hartmann mask consists of 48 lenses. ...

... Multiple exposures with small offsets in the pointing of the telescope are usually necessary or recommended for NICMOS observations. ... Dithering or chopping to measure the background associated with an -astronomical source. Mosaicing to image a source larger than the NICMOS field of view. ... Background images will be obtained by offsetting the telescope from the target to point to an "empty" region of the sky. ... Two distinct type of telescope motion are defined: . ...

Observations of stellar magnetic fields is a powerful method to study of different non-stationary effects in our Galaxy and behavior of plasma under astrophysical conditions. ... Investigations of stellar magnetism by means of Zeeman measurements of polarized spectra of different stars are one of the most significant observational programme on the 6-m telescope BTA of our Observatory. ... Laboratory for the Stellar Magnetism Study . ... Laboratory for the Stellar Magnetism Study of SAO of the RAS . ...

... 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. ...

... During the week from the 14th of June to the 18th of June I have been on work ex