Measuring the panels with photogrammetry: . ... Back fit for camera position and determine position of each target (no distance scale, only angles). ... Adjusting the panels: . North/south support cables have tieback cables that can be adjusted to pull the cable catenary close to the spherical shape. ... Results: . Rms of primary less than 1.6 mm over the beam area. plots showing results of the second round of target measurements (there was one more adjusting round after this). next previous ...

... Astrometry with the FGS, by contrast, proceeds in the reverse order; the positions of the individual objects are found first, and then a virtual plate is constructed with the help of data from the guide stars and check stars. ... Corrections based on guide star data are referred to as POSITION mode dejittering , and those based on check star data are called drift corrections . ... The adjustments to the astrometry centroids from this POSITION mode dejittering correction are typically about 1 mas. ...

... After all we cannot send a probe to the star Altair to confirm that it is 17 light years away. ... The "Bessel determined that the star 61 Cygni was about ten light years away" Earth goes around the Sun in one year, so in six month it is in the opposite position in its orbit. ... In 1838 Bessel determined that the star 61 Cygni had a parallax of 0.314 arcseconds and therefore the star was about ten light years away (today the distance is more precisely measured to be 11.4 light years). ...

... An OBJECT column gives the name of the object observed (usually a star name). ... In critical cases, it is common practice to measure sky on two or more positions around a target object, and these positions must be identified. ... A general treatment of this problem requires a column called OBJECT, bearing the usual name of the object (as in the star tables); a column labelled STARSKY, to distinguish between star+sky, star alone, or sky alone; and additional columns to identify the sky position. ...

... Boresight routine then calculates pixel positions and adjusts boresight to the minimum moment. ... Pictures Boresight of other instruments and OM OM boresight compared with startracker boresight Field Rev Prime No. objects Intended boresight (from POS, or commissioning plan) Measured boresight (from boresight .pro) AHF boresight (from AHF file) Coords of startracker pointing moment (distance) [ moment (distance) = mean of calc. position ­ measured detector ...

... This document and the attached postscript figure document an analysis that I did to determine the optimum midpoint and required ranges for both the rotator and azimuth for the 2.5 M telescope. ... I simulate a series of drift scans on the sky for tracks that cover the northern survey area. These tracks cover the range in survey latitude of -60 to +60 degrees, spaced by 10 degrees. ... Along each track the azimuth, elevation, and position angle of the CCD is computed at 1 minute intervals. ...

... Luminosity (L) · · · · A source's luminosity is the power that it emits in radiation. ... NB Astronomers often say `flux' when they mean `flux density' · SI units are Wm-2Hz -1 -26 filter · Also used are Jy 10 Wm-2Hz -1 E= РРРF d dA dt Specific Intensity, Surface Brightness (I) · Specific intensity (or surface brightness) is the power received (or emitted) per unit area per unit frequency per unit solid angle. ч F at surface of a spherical source = I · · Specific intensity is independent of distance...

Program: TRACE Purpose: TRACE plots image values at user given positions as function of distance to a plot centre (in 2-d (sub)sets). Category: ANALYSIS, PLOTTING File: trace.c Author: M.G.R. Vogelaar Keywords: INSET= Give set (, subset): Only one subset is allowed. ... XYBOX= Give size of box around one pixel: [3,3] The resulting value at a selected position is an average of the pixels in the defined box around that position. ... POSITION= Give position x, y: Physical values are allowed. ...

... Keywords: Proper Motions, Schmidt Plates, Astrometry, Guide Star Catalog, Palomar Sky Survey . In this paper we describe a program of determining proper motions from digitized scans of 1950's-era Palomar Sky Survey (POSS) Schmidt Plates and 1980's-era Palomar Oschin Schmidt `Quick V' plates that were taken for the Hubble Space Telescope ( HST ) Guide Star Catalogue. ... Arrows indicate the magnitude and direction of the proper motion for the stars. ...

... Activity 3: Measuring the Position of the Sun in the Sky . Purpose: To give students the opportunity to measure the position of the Sun in the sky using simple tools and methods. ... Alternatively, you may have students devise their own methods of relative measurement and apply them to measuring the position of the Sun in the sky. ... Rangi is the sky, and when the Sun is near Rangi's head it is summer in New Zealand. ... Read the Maori story to students. ... back to Teachers' Newsletter Main Page ...

polimplot -- Plot a polarization vector map . ... inpol = "" [name] . Input linear polarization image (in %) to plot. inpopa = "" [name] . Input image for position angle of linear polarization vectors (degrees). poi_err = "" [boolean] . ... Name of corresponding polarization position angle error image (degrees). ... This task is a flexible tool for plotting a polarization vector map from two images of the polarization and the position angle of the polarization vector. ...

polimplot -- Plot a polarization vector map . ... inpol = "" [name] . Input linear polarization image (in %) to plot. inpopa = "" [name] . Input image for position angle of linear polarization vectors (degrees). poi_err = "" [boolean] . ... Name of corresponding polarization position angle error image (degrees). ... This task is a flexible tool for plotting a polarization vector map from two images of the polarization and the position angle of the polarization vector. ...

... Bad Astronomy . ... Mad Science . ... Keep Bad Astronomy close to your heart, and help make me filthy rich. ... How did early astronomers determine the distance form earth to the sun, and what method is used today to determine distances in space? ... Since Huygens knew the Sun-Venus-Earth angle (from the phases), and he could directly measure the Sun-Earth-Venus angle (simply by measuring Venus' apparent distance from the Sun on the sky) all he needed was to know the distance from Earth to Venus. ...

... The system is based on two straight lines ("axes"), perpendicular to each other, each of them marked with the distances from the point where they meet ("origin")--distances to the right of the origin and above it, the origin being taken as positive and on the other sides as negative (see drawing below). ... One system (" polar coordinates ") uses the length r of the line OP from the origin to P (i. e. the distance of P distance to the origin) and the angle that line makes with the x-axis. ...

Astronomy Terms - To Help You Study The Universe . Articles | ... Learning about the universe, or the study of astronomy, can be fun for the individual or for the whole family. ... Learning a few simple terms will help you with this fascinating study. ... You will use a telescope or binoculars for your observation of the sky at night. ... Celestial Terms . ... Meteor or a shooting star – the light caused when a meteoroid burns up in Earth's . ... www.astronomy.net . About Astronomy Net | ...

... Sighting the telescope, first at the tree and then at pole B, you measure the angle A of the triangle ABC, equal to the difference between the numbers you have read from the azimuth plate.. ... Why triangles? ... One large surveying project of the 1800s was the " Great Trigonometric Survey " of British India. ... Everest was the one who commisioned and first used those giant theodolites; they are now on display in the Museum of the Survey of India in Dehra Dum. ... Everest . ...

These are very prominent absorption lines is most all galaxies. ... These pair of absorption lines will appear in all the spectra and they should be your principle source for determining the redshift. ... When this applet opens you will see an iconic representation of galaxies in the left hand side of the applet and a target area in the right side of the applet. ... Note: What you are doing in this excercise is identical to what Hubble did in the 1920's and you are using the same galaxies. ...

... U. Amsterdam Explanation: The GRB distance scale controversy may have just ended with a flash . Gamma Ray Bursts (GRBs) are powerful explosions occurring in seemingly random positions on the sky. ... There they found a faint but variable optical source : a potential counterpart to the gamma-ray burst that was getting brighter. Most importantly, continued scrutiny showed that this optical transient had absorption lines with a redshift of about 0.8 - the distance scale of galaxies and quasars . ...

Super Rocket Targets . NPO MOLNIYA has been designing rockets-targets for over 30 years using the great experience in crea-ting anti-aircraft guided rockets (AGR) for C-25M. On the basis of B-300 anti-aircraft rockets which expired their service life, there were designed, tested and put into the serial production the following types of the rocket - ... The analogue of this system successfully passed the state tests with the ZVEZDA-4 rocket-target. ...

Operations in Point operations use the pointer to query sets about points, delete points in a set, and move points. In all cases where interaction is required, pressing the right mouse button with the pointer in the drawing area cancels the operation. ... Report on a point in a set . ... Press the left mouse button. ... Press Delete point with the left mouse button to activate. ... Move the pointer to the new location and press the left mouse button again to register the point's new location. ...