Next: Combining Bias Frames Up: Preparing Your Calibration Previous: Input and Output . Except for summing the frames together, combining frames may require correcting for variations between the frames due to different exposure times, sky backgrounds, extinctions, and positions. ... The input frames are combined by applying a sigma clipping algorithm at each pixel. ... The input frames are combined with a variant of the sigma clipping algorithm which works well with only a few frames. ...

... The NICMOS data reduction and calibration pipeline employs file formats and software architecture techniques that are new and different from what has been used for previous HST instruments. This paper describes the FITS file format used for NICMOS data, which includes error estimate and data quality arrays for each science image, and describes the approach used to associate multiple observations of a single target. ... This group of five data arrays is called an image set, or ``imset'' for short. ...

... Using the Echelle with TUI . Using the Echelle with Remark . ... Configuring TUI to use the Echelle . Setting up the Echelle exposure parameters . ... Focusing the Echelle . ... Changing the echelle guider filters . ... Configuring Remark to use the Echelle . ... Echelle User's Manual . ... The Echelle home page is http://astro.uchicago.edu/echelle . ... Echelle Description . ... Enclosure . ... schematic CAD files . schematic PDF files . ... enclosure wiring schematic . ...

... ESO is building what will be the World's largest optical telescope array, The Very Large Telescope (VLT). The VLT Project organisation is responsible for the design and construction of the Unit Telescopes, including enclosures, optics, adapter-rotators and coating unit. ... Unit Telescopes Overview - This page is outdated, an update is in process. ... Secondary mirror (M2 Unit) - This page is outdated, an update is in process. ... Coating Unit - This page is outdated, an update is in process. ...

Next: Setting the Rest Frequency Up: Spectral Line Data Reduction Previous: Listing and Plotting Velocity . Although atlod or fits is the best place to set the velocity information, this can also be handled by the task uvredo . This task recomputes a number of the `derived' quantities (such as observatory radial velocity) which are stored in a visibility dataset. You have to select uvredo 's velocity option, and set the keyword velocity to indicate the rest frame to be used. ... UVREDO . ...

... First, we computed the mean errors of orbit parameters on the assumption of the linear connection of them with observation errors and then we compared obtained estimates with those resulting from the assumption of the nonlinearity of this connection. Secondly, we correlate orbital parameters and their errors obtained by the method of the least modulus with those obtained by the least-squares method. ...

... Archives . ... On the other hand, CHASC scientists relate more general and broad statistical inference problems in estimating the intensity map, like intensity uncertainties at each point and the scientifically informative display of the intensity map with uncertainty according to the Poisson count model and constraints from physics and the instrument, where the field, multiscale modeling is associated. As the post title [MADS] indicates, no abstract has keywords multiscale modeling. ...

Computer Ephemeris . ... Content of the Computer Ephemeris is the same as content of Soviet Astronomical Almanac (Ezhegodnik), but fully original algorithms and computer methods of calculations were used. Your requests for Computer Ephemeris for years before 2014 and your comments on its contents please direct to the author charlie@mail.univ.kiev.ua . ... Keywords: Computer Ephemerides, Computer Ephemeris, Computer Almanac, Computer Calendar. ...

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. ...

On/off position switching on continuum sources was done at 2380 Mhz with the sband narrow receiver and the correlator. ... Use the total power information, cal values, and source flux to compute tsys, gain, sefd. Fit the data to a function of (az,za). ... Include losses from pitch, roll, and focus. ... Tsys - fit. ... These plots take a closer look at the average gain fit and how the azimuth terms of the fit compare to the azimuth terms of the gain loss computed from pitch,roll, and focus. ...

... Phase Correction Algorithms | ... This page describes work undertaken at the Cavendish Astrophysics Group , developing phase correction algorithms and software for the Atacama Large Millimetre Array (ALMA). Without correction, phase fluctuations, mainly arising from the water content of the atmosphere, would limit ALMA's performance . ... The following people are currently involved in the phase calibration workpackage, based at the Cavendish Astrophysics Group in the University of Cambridge : . ...