The Setup tab is used to set various AO options and to test the AO unit.
The AO Tracking Speed is the distance a star is moved (in pixels) by a 100% optical deflection (i.e. from centered at 0% tilt to fully deflected 100% tilt) multiplied by 5. These values should be filled in using the Calibrate AO function on the Locate tab. Normal X and Y values are in the 60 to 120 range. These values may be larger if a filter wheel is installed between the A0 and the camera, due to the extra distance between the optic and the detector. The X and Y values should be within a factor of two of each other.
If star drift during the AO calibration is too great, the AO Tracking Speed values may be incorrectly set. This could occur because of very poor polar alignment or periodic error. If both the X and Y directions are incorrect by the same amount, adjusting the Aggressiveness while autoguiding would compensate for the tracking speed. However if the stars on the main exposure are oval shaped, either the X or the Y (but not both) AO Tracking Speed will have to be manually adjusted (N.B. Increasing the Tracking Speed is akin to decreasing the Aggressiveness and vice versa). Calibrating using a bright star and a very short exposure will minimize this problem. Remember that the AO calibration only needs to be done once ever, unless the hardware is modified.
The Reverse X, Reverse Y and Swap Axes check boxes are automatically set using the Calibrate AO mode on the Locate tab. However they can be set manually if the Manual Settings check box is checked. The Swap Axes check box is turned on when the X axis of the autoguider image corresponds to the Y deflection axis of the tip/tilt optic.
The Exercise controls allow for visually checking the operation of the tip/tilt optic. Remove the AO/camera combination from the telescope and look at the tip/tilt optic. When this function is activated using the Start button, the optic will repeatedly move between the four extreme positions. The X Axis and/or the Y Axis can be tested independently and the time spent while stationary (in milliseconds) at each extreme can be varied with the Speed setting. All these settings can be changed while the AO is exercising. The Stop button terminates the function.
The SNR control allow you to adjust the signal-to-noise Threshold for star detection. A higher value means the software will require a brighter, cleaner star image; a lower value will allow fainter, noisier stars to be used. The choice is a trade-off. If you set it too high, you won't be able to calibrate or track on fainter stars. If you set it too low, the software will not detect when a star fades due to clouds, momentary obstruction, etc. If it does not detect a faded out star, the AO algorithm will likely latch onto a faint hot pixel, causing the AO system to track way off target - both tip/tilt and mount bumping. If this happens the AO tracking may not be able to recover from a passing cloud. A good starting point for this setting is 50.
The Fan Speed control can override the fan behavior. The default is Auto, which means the camera decides how to set the fan based on the heat sink temperature. You can manually override this by setting the fan speed in 10% increments.
The Track Box determines the size of the tracking image displayed on the Track tab while autoguiding. A smaller Track Box will increase the update rate but will also increase the chances that the guide star is lost due to a large instantaneous deviation. In most cases a 16 x 16 or 32 x 32 track box is a good compromise.
The Test Mode option allows you to evaluate the performance of the AO unit. During a test mode exposure the AO optic will be periodically deflected from its tracking orientation to 100% x 100% (full deflection in both axes) and held for five seconds, then will return to normal guiding for five seconds. This produces an image with two sets of stars, one of which was corrected by the AO, and the other uncorrected.
Note: Dithering is no longer configured in the AO Control. See Autosave Sequence.
At bottom right there is an Options flyout menu.
Please note that the method used to send bump commands to the mount is selected using Guide tab Settings Control Via.