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PE Toolbar


The Position Editor Toolbar provides quick access to the most commonly used features from the menu bar. The buttons have the following action:

  • Open - bring up a file selection dialog to load a previously saved image.
  • Back - move backwards in image history list.
  • Forward - move forward in image history list.
  • Cut levels - bring up a dialog of showing the distribution of pixel values for the displayed image. The minimum and maximum display levels can be set either with the slider or the Auto Set buttons.

Cut levels dialog


  • Catalogs - opens the catalog navigator for defining and executing custom guide star and image server queries.  It is also useful for seeing the detailed results.
  • Images - queries the the default image server using the base coordinates of the observation selected in the Program Editor.  If no default is set then a Image Server dialog (below) queries the user to select a server.  The default can then be changed by selecting a new server from Catalog -> Image Servers in the menu bar (the current default is marked with a black dot) or by selecting an image server with the Catalog Navigator and pressing the Store Settings button (the icon of the default is shaded yellow).


Image Server dialog


  • Manual GS - opens the Guide Star Selection dialog (below) for doing quick guide star searches.  The coordinates for the search is the base position of the observation selected in the Program Editor. Likewise the Instrument is set using the instrument component of the selected observation in the Program Editor.  The Guide Star Type and the Catalog is remembered from the last query.  The combination of the instrument and guide star type determine the minimum and maximum radii and the limiting magnitude for the query. Custom queries can be constructed using the catalog navigator.


Guide star selection dialog


  • Auto GS - initiates a UCAC4 guide star query and automatically selects the brightest allowed guide star in the patrol field. This applies to the Peripheral and On-Instrument wavefront sensors; selection of GSAOI/GeMS guide stars will be described elsewhere. The allowed WFS patrol field is the union of the patrol fields for all offset positions where the WFS is set to guide (not freeze or park). This field is shown by the green line in the PE. The magnitude limits for the guide star candidates are determined by the WFS and the observing conditions constraints, and are shown in the bottom right of the Target Component when a guide star is selected.


    If a position angle of PA ± 180 degrees is acceptable for your observations, then select "Allow 180 flip" in the instrument component:

    With this option permitted the guide star selection will automatically change the PA if a brighter guide star is available at PA ± 180 degrees.