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... Computing the pointing error . ... The platform can be rotated by pulling on the tie downs or redistributing weight on the platform. ... The horn rotates through the same angle as the platform. ... The plots show the computed pointing error for different platform rotation angles (.ps) ( .pdf ): . This shows the pointing error in as you tilt the platform. ... B2209+080 has the pointing errors with no tilt. ... The computed pointing error for a platform tilt track the measured errors pretty well. ...

... sin f = y / r . cos f = x / r . ... They are now viewed as new definitions of the sine and cosine, for the polar angle f given by x and y ( a slightly different way of formulating this definition is described further below ). ... sin 2 f + cos 2 f = 1 . ... Angle . ... Many trigonometry texts define the sine and cosine slightly differently, using the so-called unit circle . ... Then the distance AB ("the sine line") equals sin a , and the distance OA ("the cosine line") equals cos a . ...

There are various kinds of generic information you can retrieve about an XPA access point by using the xpaget command. ... Each XPA access point supports a number of reserved sub-commands that provide access to different kinds of information, e.g. the access control for that access point. ... acl get (set) the access control list [options: host type acl, for set] . ... This access point is available only on the server machine. -env get (set) an environment variable [options: name (value, for set)] . ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Australia Telescope User Committee . ... Astrophysics graduate student programs . ... Facilities . ATNF facilities . ... Australian Square Kilometre Array Pathfinder . Murchison Radio-astronomy Observatory . ... Parkes radio telescope . Australia Telescope Compact Array . ... Visiting Parkes radio telescope . Visiting Australia Telescope Compact Array . ... Parkes radio telescope webcam . ...

... At the summer date, at the chosen time, the Sun is high in the sky. at point S, while at the winter date, it is low in the sky, at point W. The shadow of the gnomon is always in the plane containing the Sun and the points A and B. If AB is a thin line, the shadow will also be a thin line, the intersection of this plane with the base of the sundial. ... Summer or winter, the shadow is therefore along the same line, the intersection of the above plane and the base of the sundial. ...

... Bad Astronomy . ... Bad Astronomy: The North Star, Polaris, is a very bright star. Good Astronomy: Polaris is a middling-bright star, easily missed. ... He said it was close to Polaris, the North Star, but he also said it was in the East. ... It's natural, I suppose, to think that such an important star should be bright, but really, that's a conceit, like thinking that the Earth is at the center of the Universe. If more people knew just why Polaris is the North Star, this Bad Idea would stop. ...

... A detailed study of two consecutive bright points observed simultaneously with CDS, EIT and MDI is presented. The analysis of the evolution of the photospheric magnetic features and their coronal counterpart shows that there is a linear dependence between the EIT Fe XII 195? flux and the total magnetic flux of the photospheric bipolarity. ... In a follow-up study, we used wide slit (90arcsec240arcsec) movies of four EIT coronal bright points (BPs) obtained with CDS. ...

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 ...

These observations are aimed at fully charactering FORS1 photometric system (UBVRI zero-points, color-terms and extinction coefficients) for the Tektronix 2048x2048 pixel CCD (24µm px) . To this aim, the two Landolt/Stetson photometric fields SA95 and SA101 will be observed on a number of epochs and at different airmasses during February and March 2007. ... SA101 . ... OBs for SA101 have to be observed during evenigh twilight (exceptions are expected for the second half of March) . ...

Distribution of the analyzed SEPs with different >100 MeV proton fluxes ( J 100 ) at the microwave flux density plane ' S 9 vs. ... 1) General correspondence takes place between intensities of microwave bursts and proton fluxes - J 100 increases when S 9 and S 15 rise. ... 3) Powerful microwave bursts ( S 9 , S 15 >3000-10000 sfu ) with hard radio spectra ( S 9 < S 15 ) correspond to majority of powerful proton fluxes ( J 100 >10 pfu ). ...

This section of AMPLE enables one to make ephemeris calculations in various coordinate systems (spherical, rectangular) connected with different main planes (equator, ecliptic, horizon) and having origin in different points: geocenter, any point on the Earth surface, the Sun, any major planet, any minor planet. The choice of some minor planet as a center gives possibility to find approaches of the minor planet with any set of major planets and minor planets. ... equinox . 1950 2000 true . ...

Polaris: The North Star . ... First, Polaris is the nearest bright star to the north spin axis of the Earth. Therefore, as the Earth turns, stars appear to rotate around Polaris , making it the North Star . Since no bright star is near the south spin axis of the Earth, there is currently no South Star . Thousands of years ago, Earth's spin axis pointed in a slightly different direction , and Vega was the North Star. ... NASA Web Site Statements, Warnings, and Disclaimers . ...

... STScI-PRC00-06 LIGHT AND SHADOW IN THE CARINA NEBULA Previously unseen details of a mysterious, complex structure within the Carina Nebula (NGC 3372) are revealed by this image of the "Keyhole Nebula," obtained with NASA's Hubble Space Telescope. ... This region, about 8000 light-years from Earth, is located adjacent to the famous explosive variable star Eta Carinae, which lies just outside the field of view toward the upper right. ...

... Magnetic fields, subatomic particles, etc., traveling in different directions fill the universe. Do they deflect or otherwise affect one another? If so, isnт??t the information we get from them distorted? ... Neutrino astronomy, which is still in its infancy, is attractive because neutrinos interact so weakly with matter that few of these distorting effects occur. Get instant access to subscriber content on Astronomy.com! ...

... In some ways, the Internet is the ultimate on-line service--but only if you know where to look. ... Some are created by automated agents who systematically walk the Web in search of new resources or solicit information from Internet users. ... The WWW Virtual Library from CERN offers topical and geographic indexes to Web sites. ... The Online Whole Internet Catalog is a hypertext version of the resource guide from the Whole Internet Catalog from O'Reilly Associates. ... Library of Congress . ...

... If the Earth is round, the Sun must be north of the equator in northern summer, and south of the equator in northern winter. ... From the Earth's perspective, the Sun is spiraling from north to south and back again along the ecliptic (see figure 7 ). ... The round Earth, at the summer solstice. ... If the rotation axis of the Earth is tilted with respect to its orbit, the equator bobs back and forth, causing the Sun to be north for half the year, and south for the other half (see figure 9 ). ...

... 295, 2003 H. E. Payne, R. I. Jedrzejewski, and R. N. Hook, eds. The MAST Pointings Tables Pro ject Karen Levay, Paolo Padovani1 , Randall Thompson, Megan Donahue, Michael Corbin Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 Abstract. We have undertaken a pro ject to create a database of all HST imaging observations organized by position on the sky. ... Each sky region was called a "pointing." ... Users select the instrument pointings table they wish to search. ...

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); . ...

ATM Forum Message . ... 9 Point Cell . ... You really don't need a 9 point cell for the mirror unless the last of the dobs used a much thinner piece of glass for the mirror. A regular 3 point cell will work just fine and will be distorting the glass a lot less than the probable errors in the mirror surface are by a huge margin. ... www.astronomy.net . ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...