Display 3: The Turret Display

This mode shows the current position of both telescope axes, as well as the position of the target. It is mainly used for testing purposes, but can be a useful aid for confirming the telescope position after initialisation.

Figure 5: The Turret Display

Each ring represents an axis of the telescope. The line from the centre to the edge represents the current telescope position, while the green dot outside the ring represents the desired position (i.e. target position). The lines are red while they are distant from the target and green otherwise.

The azimuth axis is drawn in such a way (with the camera at the bottom) so that it corresponds with the view seen from the live telescope video feed on the control box (see appendix D). This helps the observer confirm that the position reported by the software corresponds to the actual position of the telescope.

The two white markers on the elevation axis represent the two elevation endstops. Should the telescope hit either of these, then it will park automatically. Red markers denote areas where the encoder strips are dirty. The telescope may well have problems tracking or initialising at these areas.

Other information on the display includes target and telesope Az/El coordinates as well as current telescope status (parked, tracking, stopped etc.). Also, prior to initialisation, the approximate, last known position in azimuth is written in red. It is good to check this before attempting to initialise the telescope.