Next: Sky Subtraction Up: Construction of Flat Previous: Standard construction . For a number of projects where very deep integrations and accurate flat fields are required, and the targets are point sources or much smaller than the frame size, the sky background itself can be used to calculate the flat field. ... Use STATISTICS/IMAGE to calculate the image median, and COMPUTE/IMAGE to divide by this to get the normalised flat field. ...

The NICFPS:Dither:Point Source Random script allows you to take a sequence of exposures in a square pattern plus a point in the middle. This pattern is typically used for point sources. ... Any dither point may be omitted by unchecking its checkbox before running the script. ... Dither pattern without randomization . ... Randomization 1. ... Dither pattern with randomization Thanks to Corey Wood for the first implementation of randomization and for the images used in the documentation. ...

Table 3.1: Designations of Special Targets . Table 3.2: Target Categories . Table 3.3: Descriptive Keywords for STAR and EXT-STAR . Table 3.4: Descriptive Keywords for STELLAR CLUSTER and EXT-CLUSTER . Table 3.5: Descriptive Keywords for GALAXY . ... Table 3.13: Bright-Object Constraints . The use of "FIXED_TARGETS" and "GENERIC_TARGETS" are described in this chapter. ... In this chapter, each heading has a description followed by a keyword in square brackets (e.g., [ Number] ). ...

... POSITION= Give central position: [0,0] ANGLE= Give angle (deg), w.r.t North towards the East: GRIDOUT= New grid spacing of [spacing in longitude] rotated axis: POINTS= Give number of pixels on rotated axis: [Number of pixels on longitude axis] SLICES= Number of slices above and below slice [0,0] through new projection centre. Total number of slices cannot exceed 256. SPACE= Spacing between slices: [grid spacing in latitude] OUTSET= Give output set: PLOT= Create plot of slice? ...

The XImtool control panel is the main interface for the XImtool display program, on which SAOtng is based. The SAOtng GUI duplicates the most of the functionality of the control panel in its menu and accel buttons, but the control panel is offered as a window-based alternative to run-of-the-mill menus. ... Tile Frames . ... The text display window gives the field X,Y center, X,Y scale factors, and the X,Y zoom factors. ... Fit Frame makes the display window the same size as the frame buffer. ...

... The tension in members of the telescope changes as we move the dome, ch, azimuth, and tiedown tensions. The lifetime of a beam is counted in the number of times the change in tension goes through a cycle. ... Examples of telescope motion with corresponding unbalanced moment. ... The number of cycles were computed for : 5000, 10000, 15000, 20000 kipFeet momemnt change. ... The number of cycles on the telescope was computed using the change in the unbalanced moment (at a corner). ... cycles . ...

... LiveAudio is LiveConnect aware. Using LiveConnect, LiveAudio, and JavaScript, essentially any event that can be described programmatically using the JavaScript framework can trigger a sound event. ... For these methods to be available to JavaScript (and the web page), you must embed a LiveAudio console (any console will do, it can even be hidden) somewhere on your page. play({loop[TRUE, FALSE or an INT]}, '{url_to_sound}') . ... HTML> . BODY> <EMBED SRC="sound1.wav" . ... Play the sound now!< ...

... Exposure Time Calculator (ETC) . ... ESO - Public Surveys . ... the recommended values to use for DIT, . ... Detector on-chip integration (DIT): seconds. to your chosen value - a separate page gives recommended values to use for DIT - for modes 1 and 2 below you may wish to start with the maximum recommended values as these will minimize the effect of read noise (a total object exposure of Y secs with DIT=X secs will produce Y/X lots of read noise) and give you a lower limit on the time needed. ...

... List of SAS threads . This thread contains a (very!) simple standard XSPEC session for fitting data from the X-ray cameras. ... Start XSPEC . ... Load spectrum data: . ... response 1 PN.rmf . ... plot data . Fig.1: XSPEC data plot . Ignore bad channels in data: . ... The latter, the maximum number of channels to bu summed. plot data with model adjustment and e.g. the residuals (alternatives, ratio data/model, absolute chi-squared, etc) . ... Fig.2: XSPEC data, model and residual plot . ...

... Readability |Check number: 1 | Description: Header existence for each |Evaluation (always/often/sometimes/| |source file and for each method, class, |never) : | ... Description: Naming conventions existence |Evaluation (always/often/sometimes/| |(variables start with lowercase, then |never) : | ... limited and commented |(always/often/sometimes/ | ... Description: Error message are formated : when an|Evaluation | error or an exception is raised, report the |(always/often/sometimes/ | ...

Astronomy Discussion Forums . Forums: . ... How Do You Feel About Numbers? ... Post Message | ... Posted by Richard D. Stafford, Ph.D. on September 15, 2002 16:22:25 UTC . ... Wait - harvey1 - September 15, 2002 - 22:20 UTC . I don't follow you! - doctordick - September 16, 2002 - 14:59 UTC . ... www.astronomy.net . About Astronomy Net | ... Forum posts are Copyright their authors as specified in the heading above the post. "dbHTML," "AstroGuide," "ASTRONOMY.NET" & "VA.NET" . ...