... The source-list file produced by omdetect contains a list of the positions of all the detected sources, the parameterizations of their shapes, their extracted count-rates, and corrected count-rateswhich contain some of the corrections that are needed to convert the raw rates to the rates that can be used to compute instrumental magnitutes. ... For example, a source with a bad pixel and lying on or close to a read-out streak would have bits 0 and 1 set and thus have a quality flag value of 3. ...

... Computing the true count rates for digital data. ... The following equation is used to find the count rate. x = ( raw counts / sample time ) . ... True count rates for digital data are corrected by using the first equation for a point source and the second for an extended source. a = ( y - pre_amp - darkrate ) / ( highvolt x pt_effic ) . ... True photocurrents (count rates for analog data) are corrected by the first equation for point sources and the second equation for extended sources. ...

Next: Bivariate polynomial interpolation Up: Echelle Spectra Previous: Removal of particle . The estimation of the background is one of the critical points in the reduction of echelle spectra for two reasons. ... diffuse light in the interorder space coming from adjacent orders. sky background spectrum . ... These locations are defined when performing the order definition (command DEFINE/ECHELLE or DEFINE/HOUGH ) and can be displayed by command LOAD/ECHELLE . ... Sky background definition . ...

... Next: The PROS Big Up: Software Systems Previous: Data Reduction Software . ... The srcinten task provides PROS users with a tool to compute count rates for point sources in the ROSAT High Resolution Imager (HRI). ... Corrected upper limits are cited at locations where the count rate falls below the source detection threshold. ... Srcinten is a new PROS task that computes and applies the above correction factors to the net counts in a user-specified aperture. ...

. Next: Charged Particle Subtraction Up: *qpspec* - Extraction of Previous: Spectral Extraction of Point . When analyzing extended sources the background must be obtained from a region well separated from the source. To correct the background for the differential vignetting (i.e., the difference between source and background vignetting) of the ROSAT mirror, set the vign_corr flag in qpspec to yes. For example: . xs > qpspec vign_corr=yes . rsdc@cfa.harvard.edu . 1998-06-10

The pitch, roll, and focus errors of the telescope (measured and computed in AO9 survey and tilt sensor pitch,roll ) can be corrected by using the tiedowns. ... Tiedown positions to correct the pitch,roll, focus errors versus azimuth for za 2 through 20 degrees. ... The pitch, roll, and focus errors are plotted versus azimuth for za 1 to 20 degrees (the color changes every two degrees) . ... The pitch error is on the top and the roll error is on the bottom. ... The pitch and roll errors versus za. ...

This page was created by the IDL library routine mk_html_help . ... mk_html_help . at the IDL command line prompt. ... to calculate CHIANTI line intensities and continua, to create a synthetic spectrum. ... WRITTEN : Ver.1, 7-Nov-01, Giulio Del Zanna (GDZ) and Peter Young (PRY) MODIFICATION HISTORY: V.2, 7-Nov-01, GDZ . Fixed a small bug (now the spectrum plot is always plotted within the widget), and modified the option to add continua. ... Added extended details in the ascii output spectrum. ...

... We present methods of comparing theoretical predictions for the anisotropy of the Cosmic Microwave Background Radiation (CMBR), with the results of various experiments. ... Temperature flucuations . ... Most models of structure formation in the universe predict anisotropies in the CMBR. ... Therefore one must take into account not only the theoretically expected value of the temperature fluctuation but also the so-called cosmic variance, i.e. the theoretical error due to observing only one universe....

The technical memorandum: Time and Time Interval Measurement with Application to Computer and Network Performance Evaluation (PostScript) describes a number of techniques for conducting experiments typical of computer network and transmission systems engineering. ... The usual data collected during a performance run of some experiment might include time offsets, time delays, frequency offsets and various error statistics. ...

... ATNF Home . ... About ATNF overview . ... Australia Telescope Steering Committee . ... Murchison Radio-astronomy Observatory . ... Parkes radio telescope . ... Parkes | ... Parkes projects/positions database . ... R.J. Sault, G.J. Carrad, P.J. Hall, J. Crofts, 2000, ``Radio path length correction using water vapourradiometry'' submitted to Proceedings of WARS 2000 . Bob Sault, Peter Hall, Graeme Carrad, 1999 "Atmospheric phase correction for the ATCA" , presented at URSI 1999 (Toronto, Canada). ...