Field Steering GUIThe field steering GUI enables the AO operator to move the field steering motors in either NGS or LGS mode, including appropriate telescope counter moves. It also displays the status of the AO loop and if ShARCS has an exposure in progress. There is also a tool to assist with determining the desired TUB rotation for either direct imaging or spectroscopy.
The field steering GUI is a TCL/Tk program that runs on shanevnc and is started at the command line by typing fieldsteer.tcl. The GUI is displayed in Figure 1.
The GUI is divided into different regions for the various operations.
The top section (Figure 2) is dedicated to moving the field steering motors and/or telescope. There are two modes, either moving the telescope, Telescope Move section, or moving the star in ShARCS field of view, Move Star section. Enter the size of the move in arcseconds in the central box of section then click the desired direction. Clicking the corner buttons in the Telescope Move section will move both directions by the entered number of arcseconds, for example 5 NW will move 5 arcsec North and 5 arcsec West. The total offsets for the field steering motors are displayed in the next section (Figure 3) for both the NGS and LGS field steering motors. The corresponding telescope moves in arcseconds East and North (if they were performed) are shown next, for both NGS and LGS moves. Total Telescope offsets from the target position sent to the telescope are shown on the following line.
Figure 2: Telescope Move and Move Star GUI
Figure 3: Field Steering Position and Telescope Offset Display
What actions are performed and which motors are moved for the Telescope Move or Move Star are determined in the NGS-LGS section of the GUI (Figure 4), which has checkboxes for the desired actions. At the top there are two radio buttons for selecting whether you want to move the NGS mode (WFS steering motors) or LGS mode (TT Cam X and Y) field steering motors. The mode should agree with the Operation Mode shown in the ShaneAO GUI for most purposes.
The subsequent options are enabled when the checkbox is red, and
disabled when the checkbox is grey. Operations that are checked will
be done any time you do a Telescope Move or Move Star, or click the
Back On-Axis button.
Move telescope moves the telescope, taking into account the position angle of the instrument (TUB rotation) when using the Move Star GUI. The executed offsets are displayed in the Telescope Offsets portion of the GUI (according to whether NGS or LGS is selected above).
Move Fieldsteer Motors moves the appropriate motors for NGS or LGS mode as selected above. Offsets from on-axis are displayed in the Field Position portion of the GUI.
Auto Open Loops makes sure that the AO Loop(s) are opened before moving any motors or moving the telescope. This should always be checked for regular operations.
Auto Close Loops closes the AO Loop(s) after any motor or telescope moves.
Figure 4: NGS-LGS GUI
The ShaneAO instrument may be rotated to a desired position angle on the sky by rotating the Telescope Utility Bin (TUB) to which it is attached. The default TUB rotation of 74.0 degrees, corresponds to an imaging PA of 0.0 degrees (North up and East to the left on ShARCS). However, the slit for spectroscopy is nearly horizonal in ShARCS field, meaning that to position the slit at PA=0.0 degrees, the TUB must be rotated to 158.5 degrees. Remembering these offsets (including the limitations of TUB rotation) can be challenging. Hence, the Position Angle section of the GUI (Figure 5) is designed to help calculate the TUB angle given the desired PA. The current TUB rotation is displayed at the top of the section and the entry box below it is for the desired position angle in degrees East of North. Pressing the Set button will update the Desired TUB and TUB(Slit) values for direct imaging or spectroscopy, respectively.
Figure 5: Position Angle GUI
The bottom button bar of the GUI has three buttons:
Back on-Axis which moves the field steer motors and/or telescope back to the on-Axis position based on which items are checked in the NGS-LGS portion of the GUI above.
AOReady is used during ShARCS dithering scripts when the scripts are not in Auto Close Loop mode. In this case the AO operator will close loops after motors and the telescope are done moving, make sure everything is working properly, then press the AOReady button to indicate to the script that it can continue.
QUIT exits the software.
In between the buttons are status indicators for the AO Loops and if ShARCS has an exposure in progress. If the AO loops are closed, the indicator will be green, otherwise it is grey. If a ShARCS exposure is in progress, the indicator will be green, otherwise it is grey.
Figure 6: Buttons and Status Section
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