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Position Angle and Camera Offset

The first (left-most) panel displays the current Position Angles of the selected FOVI in TheSkyX (TSX), the Pyxis rotator and the attached camera (Cam). If there were no rotation offset in mounting the camera on the Pyxis these would be all the same. In general there will be an offset, which can be compensated using PyxisControl.


The most precise way to evaluate the offset is to take an image and then use a "plate solving" tool, such as the Image Link funtion in TheSkyX, to determine the image Position Angle.


Without moving the Pyxis after determining this angle, enter the value in the field next to the Set button. It can be entered in any format (TheSkyX typically gives a value in degrees and minutes) and the selected format chosen from the drop-down menu below the entry field.

Then press the Set button. The TSX and Cam Position Angle displays will change to match the entered camera angle, but the Pyxis display will remain unchanged. From now on all commands to set a Position  Angle will refer to the camera angle, and the required Pyxis angle will be computed in the background.



If the Image Link gives a result close to 180° and you think it should be near 0°, or any similar situation, you can use the check-box labelled -180°. Enter the result given by Image Link and tick the box: the camera offset will be computed for a position rotated by 180°.


The derived camera offset angle is saved from session to session, but the measured camera angle is not since this value is only relevant at the time the offset is measured.


In the centre of this first panel is another entry field, next to the button marked GoTo. This is used to directly enter a target Position Angle. On pressing GoTo the Pyxis and the TheSkyX FOVI will move to this Position Angle. Values will also appear in this box when angles are selected by other means (see Incremental Control and Rotation Dial).

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