Target Acquisition and Guiding

PMAS provides two ways of using cameras for field acquisition and guiding:

  • the standard 3.5m Telescope TV Guider System
  • the internal PMAS Acquisition & Guiding CCD Camera


    • Fig. 1 shows the dual linear stage for the Calibration Unit and the A&G Optics with Pickoff-Mirror in the middle of the telescope flange opening. Provided the Calibration Unit has been moved out of the telescope beam and has reached its parking position, the A&G Optics stage can be moved to select between the TV-Guider and internal A&G CCD system (check PMAS Status GUI, Fig. 2 ) :
  • Status GUI : AG STAGE POS = IN (green flag) indicates that the Pick-off Mirror is in the beam, deflecting light towards the internal A&G CCD Camera

  • Status GUI : AG STAGE POS = OUT (red flag) indicates that the Pick-off Mirror is out of the beam, which is directed towards the standard 3.5m TV-Guider configuration
    • Selecting between one mode or another is accomplished through pics_gui, pulldown menu "SetMode" , option "Observing" .
    The 3.5m TV-Guider System is recommended for applications which require real-time characteristics and a quick response, e.g. when checking the pointing of the telescope. The internal A&G CCD is superior for precise centering of targets on the PMAS Integral Field Unit, and when photometric information is desirable.



    Operation of the TV-Guider is described in the following Manuals :

    CAHA 3.5m TV-Guider User's Manual
    CAHA 3.5m TV-Guider Commands
    TV Guider Control Panel
    TV Guider Video Display




    Operating the internal A&G CCD Camera :

    Fig. 3 gives an impression of the appearance of the IDL widget pics_ag , displaying a full 1Kx1K acquisition field.
    Note orientation: North to the LEFT, East to the BOTTOM.

    The pics_ag GUI provides the following pulldown menu options for operating the camera:

    File : "Load A&G Image from disk" load image from disk and display in main window
    "Print Fits Header" print FITS header of most recent file in display
    "Info picsdb" print content of picsdb status array
    "Set A&G data path" set data path to new direction
    "Set A&G prefix" set prefix of FITS images to be acquired
    "Print Log Form" print observing log sheet on laser printer
    "Quit" finish pics_ag
    Options : "set DISPLAY min / max"
    "set DISPLAY histequ"
    "set DISPLAY median +/-5%"
    "set DISPLAY histequ"
    "set DISPLAY median - 5% / + 1*sky"
    "set DISPLAY median - 5% / + 5*sky"
    "set DISPLAY locut,hicut"
    "locut,hicut = "
    "locut = "
    "hicut = "
    "LARR on/off "
    "Find Threshold"
    N_exp : "1 frame"
    "2 frames"
    "5 frames"
    "10 frames"
    "20 frames"
    "1000 frames"
    Exposure Time : "0.5 sec"
    "1 sec"
    "2 sec"
    "5 sec"
    "10 sec"
    "20 sec"
    "30 sec"
    "60 sec"
    "120 sec"
    "300 sec"
    Binning : "1 x 1"
    "2 x 2"
    SetWindow : "50 x 50 (Guiding)"
    "100 x 100"
    "200 x 200"
    "point Cursor..."
    Zoom : "x1"
    "x2"
    "x4"
    "x8"
    "x16"
    "x1 with fit"
    "x2 with fit"
    "x4 with fit"
    Find : "find stars > 200"
    "find stars > 500"
    "find stars > 1000"
    "find stars > 2000"
    "find stars > 5000"
    "find stars > 10000"
    Pointing : "Telescope Offset"
    "Telescope + AG Offset"
    "Pointing & Offset"
    "Blind Offset"
    "GET Offset"
    "GO Offset"
    "CHECK Offset"
    Filter : "Filter 1"
    "Filter 2"
    "Filter 3"
    "Filter 4"
    TMTOP : "A&G Unit in"
    "Cal.Unit in"
    "TMTOP park"
    Focus : "AGFOC Series"
    "AGFOC set manually"
    "Telescope Series"
    last change : 07/12/2002 mmr | Comments AIP | CAHA