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SiTech

1,514 bytes added, 20:24, 11 May 2020
/* Making a pointing model using SHOC */
6. In the Script window: <br>
Select the Plate Solve Stuff tab, and enter the number of calibration points you want to include in the model (100-150), the exposure time (depends on sky conditions, but typically ≤8s), SHOC binning (1) and the delay between the telescope settling and the image being taken (7s is reasonable - note that the dome needs to settle in this time) and make sure "Wait for rotator" is ticked to stop the image being taken while the rotator is getting into position.
Click "Make PointXP Run". The model will start gathering points with the telescope pointing South, so you can either rotate the dome to the South before running the script, or press "Play", then "Pause" while the dome catches up with the telescope- you can check the dome position in the "Dome" tab of the Dome Control GUI. This is the only time during the script that you would need to pause on account of the dome. Note that the way to resume the script is to click "Unpause", not "Play".
The script then moves the telescope from calibration point to calibration point in numerical order, taking an image with SHOC, using Astrometry.net to match the image to a catalogue, determining the position of the telescope, then moving on the telescope to the next point. Things to watch (lots!):<br>
* The SiTechCamera GUI displays each image. If points are failing to calibrate, check whether there are stars in the images.
7. If an image fails to calibrate, you can return to that point when the script has finished running.Left click on the failed calibration point in the Skyview window.It'll create a pop up saying e.g. "This is future cal point #86" click on that, then in the blue pop up window that follow, click "GoTo". Click "Do a single photo-init" in Script window. It will take an image with the same camera parameters as were run in the script, unless you first e.g. adjust the exposure time, then click "Save PointXP Script Settings". If the image is solved successfully, a pop up window with a few options will appear - click on "Load cal star" then "OK".
8. To examine and edit the parameters of the resultant pointing model, left-click on the SiTechExe GUI "PointXP" button to open the PointXP window. Note that this does not update while the script is running, so you'll need to close and reopen the window to register new points. A typical pointing model for Lesedi has RMS≤2", Peak≤7". Points can be deleted by clicking on them in the display (deleted points turn red) or toggling "true" and "false" on the "CalPoints" tab, where you can also sort the list of points by e.g. error to match the points on the plot. Phi corresponds to azimuth, theta to altitude. The sensitivity parameter should be low, certainly <300. 9. Save the model by clicking "Save Text Calibration File" on the Main PXP tab of the PointXP6 window. The naming convention is YYYYMMDD_SHOC_Right_NorthUp_150points.PXP. If you intend to use the model, also save it as AutoLoadRight.PXP (overwrite existing file) so that it is loaded automatically when selecting the SHOC port. The model file selected for each port is set on the Tertiary Mirror tab of the SiTech TCP Focuser GUI (currently /usr/share/SiTech/SiTechExe/AutoLoadRight.PXP).
== Troubleshooting ==
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