The area below the "Specify Orientation Ranges" radio button displays the current set of orientation ranges for the selected aperture. These will initially be loaded from the orientation ranges specified for the visit. By selecting "Specify Orientation Ranges" the displayed orient ranges become active and can be selected and modified by the user. Selecting a particular entry will cause the current aperture to rotate to the mid-point of the range. The "Add", "Edit", and "Remove" buttons at the bottom of the window allow for modification of the displayed orient ranges. The ranges are written back to the proposal when the user selects the "Save" button at the top of the VTT tool window.
By selecting the "Show acceptable orientation ranges", you will obtain a colored circle within the currently selected aperture. The circle indicates acceptable (green) and unacceptable (red) orientations, consistent with the specified orientation ranges. When the aperture is rotated, the box displaying the orientation angle is colored green or red, according to the acceptability of the angle. (Note that the "Circles" button on the top tool bar must be on.)