... 0.1 DN rms . ... Error larger for warm pixels; absolute error uncertain because of dark glow . ... Visible, near UV . ... Residuals in CTE correction . ... 3% rms (at 100 DN) . ... Aperture correction . 4% rms focus dependence (1 pixel aperture) . ... 1-2% field dependence (1 pixel aperture) . ... 1% rms max (28 days after decon) (filters bluer than F555W) . ... 2% rms for broad and intermediate filters in visible . 5% rms for narrow-band filters in visible . 2-8% rms for UV filters . ...

Next: Geometric Corrections Up: Raw to Calibrated Previous: Artifacts . ... The majority of modern detectors (e.g. CCD, diode--array or image tube) have a nearly linear response while photographic emulsions are strongly non--linear. Even for the `linear' detectors, a number of corrections must be included in the intensity calibration. ... A mathematical function is used to transform data from detectors with non--linear response to a more linear domain. ...

... epiclccorr (epiclccorr-1.0.8) [?? ... epiclccorr will treat all these corrections individually, developing and designing specific algorithms to correct the Relative Corrections . GTIs correction will be calculated using the GTI extensions located in the time series file, if any. ... Exposure correction is the time inside each frame where the CCD is taking data correctly (no counting or MIP problems). ... This correction will be calculated using the Live Time and Frame Time values of each mode. ...

... The first step to improve the FORS calibration is therefore to obtain data to allow a computation of the illumination correction across the field. ... Another limitation on the calibration accuracy has been the brightness of the Landolt standards which have forced the use of extremely short exposures introducing small but non-negligible shutter-time errors and also resulting in a very small number of useful standards per frame. ...

. Note: This material is from a 1994(!) Talk about CCDs - the physics remains the same, only the detector size has increased since then. ___________________________________________________________________ The Electronic Universe Project e-mail: nuts@moo.uoregon.edu

... The experience of determination of the link between radio sources and dynamical reference frames is presented. To obtain this connection we used a series of very long baseline interferometry (VLBI) observations of the spacecraft Phobos-2 and angularly nearby quasars. ... The dynamical reference frame is determined by equator and equinox of these ephemerides. ... References . ... The relative orientation of the radio and dynamical reference frames can be described by a sequence of three rotations . ...

... Go to new wiki . ... All LBA data correlated at Curtin since 1 January 2010 do not have SEFD amplitude scaling applied at the correlator. ... If the VLBI structure of the calibration source(s) is well known, and/or VLBI or total flux density monitoring data exists, and/or the simultaneous local ATCA data are available, then these additional data can provide useful checks to estimate the flux density on LBA baselines and gauge the accuracy of the VLBI calibration/adjust scaling factors where...

... A common cause of errors in CCD differential photometry is an improper calibration of the array. ... Figure 1: Differential photometry as a function of the position on the CCD for three stars in a field observed with the University of Bochum 0.6m telescope at the ESO La Silla observatory. ... These variations are quite different from star to star. ... Differential data computed between widely separated stars can show errors of up to about 0.1 mag when a night-sky superflat correction is applied. ...

System for high-accuracy determination of ephemeris and time corrections (SVOEVP) GLONASS A.Yu. ... 3 Purpose of SVOEVP The system for high- accuracy determination of GLONASS ephemeris and time corrections ( SVOEVP ) is intended for provision of high- accuracy solutions of user navigation and time determination problems: in real time by refining SVOEVP adaptive parameters of S/C GLONASS motion model and measurements model, by calculating SVOEVP calibration corrections for user ...

Next: The STScI NICMOS Calibration Up: No Title Previous: CONICA: The high resolution . The STScI NICMOS Calibration Pipeline . Introduction . ... Dark Current Subtraction . ... Input Data . ... Scalar Background Subtraction . 2-D Background Subtraction . ... Status and Goals of the NICMOS Calibration Plan . ... Photometry . ... Photometric Performance of NICMOS . ... NICMOS Photometry. ... ST-ECF Grism Spectrum Software for NICMOS Grism Data . ... Analysis . ... STScI NICMOS Software . ...

... A document window is shown, with 8 lines (numbered 1 to 8), each 24px high. The text of the "outer" box (at the end of line 1, halfway into line 2, and halfway into line 3) is shifted upward 12px. The text of the "inner" box, thought shifted upward as well, has been relatively positioned so that it lies in its normal flow position at the end of line 2. ... The lines, as they appear in the image, contain: Start 1 Beginning of body contents. 2 of outer contents. Inner contents. ...

To give a relative path to a file below your current directory: pwd (prints the current directory) /home/eucs/jane (the full pathname to the current directory) ls -l presentation/docs/oview.html (lists information on the file) . ... To define a file that is in another directory: pwd (prints the current directory) /home/eucs/jane/presentation/docs (the full pathname) cd ../illustrations (use relative pathname) pwd (check the current directory) /home/eucs/jane/presentation/illustrations . ...

... 313 = 0.108 AOT= 0.036 - 0.749 12 14 (Path Radiance): 3 MODIS/Terra (=466 ); 28.07.2001, 05:50 GTM 15 : 31 MODIS/Te rra (=11 ); 28.07.2001, 05:50 GTM 16 ; 17 MODIS/Terra: , 2001 . 18 ' ' : MODIS/ Terra, , 200 1 . ... 65 MODIS /TE RRA 1 284 286 288 290 292 294 296 284 286 288 290 292 294 296 , , . ... 291 .2 = 2 .7 0 MODIS /TERRA 2 284 286 288 290 292 294 296 298 284 286 288 290 292 294 296 298 , , 26 , ETM+/Lansat-7 MODIS/Terra ! ...

Microsymposium 38, MS083, 2003 (A4 format) MERCURY: LOCAL VARIATIONS OF THE PHOTOMETRIC RELIEF. ... Because of trajectory and pointing angle constraints the planet could be observed from Mariner 10 only over a small range of phase angles between about 75o and 110o. Therefore the photometric investigations are restricted to measuring the distribution of brightness on the Mercurian disk. ... Raw versions of real-time processing pictures FDS 0000984 and FDS 0000986 were used (images 196 and 202). ...

... Stansell Consulting Companion Article GPS World, Sept. ... Douglas Loverro ­ why replicate C/A code? Steve Lazar ­ first analysis and R/C code option LCDR Richard Fontana ­ led coordinated JPO effort Wai Cheung ­ organized, hosted, managed Dr. Charlie Cahn ­ codes, analyses, insight wisdom Dr. Phil Dafesh ­ lower bit rate hardware demo Rich Keegan ­ validated receiver feasibility Tom Stansell ­ coherent carrier, guided, presented Dr. A.J. Van ... L2C vs. ...

... Subject and Problems of Stellar Astronomy. ... Plane of Galaxy, Methods of Its Location Determination. ... Stars Distances. ... Other Methods of Stars Distances Determination. ... Tangential Velocities, Their Determination by Self-Motions. ... Determination of Solar Apex and Spatial Velocity by Radial and Spatial Velocities of Stars. ... Features of Orientation and Parameters of Peculiar Stellar Velocities Ellipsoid. ... General and Selective Light Absorption in Galaxy. ... Darc Clouds in Galaxy. ...

... Credit: AAVSO Explanation: Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). Working at Harvard College Observatory , Leavitt precisely calibrated the photographic magnitudes of 47 stars to which all other stars could be compared. ... Publications with keywords: scientist - Henreitta Leavitt - star . Publications with words: scientist - Henreitta Leavitt - star . ... The Quintuplet Star Cluster . ...

... 2000 September 3 . Henrietta Leavitt Calibrates the Stars . ... Explanation: Humanity's understanding of the relative brightness and variability of stars was revolutionized by the work of Henrietta Swan Leavitt (1868-1921). ... Leavitt discovered and cataloged over 1500 variable stars in the nearby Magellanic Clouds . From this catalog, Leavitt discovered that brighter Cepheid variable stars take longer to vary, a fact used today to calibrate the distance scale of our universe . ...

UFO Forum Message . Forums: . ... Post . ... It Really Is Relative . ... Post Message | ... If you are on the Earth the moon does not rotate around its own axis. ... www.astronomy.net . About Astronomy Net | Advertise on Astronomy Net | ... Unless otherwise specified, web site content Copyright 1994-2016 John Huggins All Rights Reserved . Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...

... The possibility to use the electrostatic approximation to calculate the polarizability allows one to consider practically any shape scatterers - from the regular ones (ellipsoid, cylinder, disc) [ 7 , 274 ] to those with an arbitrary shape, structure and anisotropy [ 308 , 309 , 313 , 405 ] (in the last case the polarizability tensor should be found numerically) - using the theory of the Rayleigh scattering. ...