Taking High Speed CWFS Data for Image Quality Measurements

Part of the Image Quality Improvement Project at the Hobby-Eberly Telescope will include the use of a high speed CWFS imaging to measure seeing in sub-apertures

1. Select a 6-7th magnitude star (i.e., from the bsc catalog) and run shuffle on it with IFU=000 (the IHMP). Choose a star which transits about 20 minutes from when you start the test.

target_setup -cat bsc 983 W -ifu 000 -to

2. Make sure the DIMM is running the whole time.

3. Ask the TO to power on the CWFS and restart PAS (can do this while going_next), the RA will also need to restart their TCS GUI.

4. Get on this trajectory with "go_next". Ask the TO to setup on the IHMP position from wiki (handshake from ACQ to a guider).

5. Center and activate a WFS.

6. Make sure all probes are storing images.

7. Ask the TO to retract the ACQ mirror and insert the CWFS mirror.

8. Offset from IHMP to CWFS with syscmd -T 'offset_trajectory(dx_ang=-5.1, dy_ang=-3.9, adjust_probes="true")'

9. Try using a 1-5s exposure time for CWFS, and be sure that the "process" and "store" checkboxes are enabled on the "CWFS control" tab in the TCS GUI.

10. Look at CWFS x and y offsets (in the CWFS metrology tab) and adjust the offset command (listed above) until offsets are less than 0.3".

11. Once the CWFS is well-centered, run this command to allow VimbaViewer to take control of the CWFS:

syscmd -p 'CWFS_RelinquishControl()'

12. Start the VimbaViewer by running: vimbaviewer (aliased to /home/het/rbryant/Vimba/Vimba_2_1/Tools/Viewer/Bin/x86_64bit/VimbaViewer)

13. The first window that starts up is the camera select window. Click the check box next to the CWFS camera (it is the only one not black-ed out since you just relinquished it). Do not exit the Camera Select Window or the Camera Control Window (which pops up when you click the check box) will also exit.

14. Load CWFS camera settings file by clicking this button:

Choose the file called /home/mcs/astronomer/cwfs_4x4.xml . This will set the binning and ROI settings correctly.

15. In the "Brightness" tab, set the exposure time between 10,000 and 20,000 micro-seconds. If you like, you can verify that the ROI tab shows that the binning is 4x4 and the ROI numbers are OffsetY:0, OffsetX:56, Height:296, Width:296, as shown in the screenshot below

16. Click "play" icon to see images, then click "stop". To check for saturation, click File --> Save Image As and save the most recent image as tiff somewhere easy like {~/test.tiff}. You can open this with ds9 -photo test.tiff to see how it looks. Adjust exposure time if necessary.

17. Set the parameters for an image series by selecting File->Image Series Options... from the File menu. You may have to create the CWFS/ directory in the night's directory.

Format = .tiff

Name = YYYYMMDD_HHmm where YYYYMMDD_HHmm are year, month, day, hours, and minutes), ... for each image series that night

Destination Path = /hetdata/data/ImageQuality/YYYYmmdd/CWFS

Number of Images = 2000

16. Run this image series (taking 2000 images should take about 3 minutes), and the speed should be around 40-50 FPS (fast enough).

17. Wait 1 minute and repeat step 15 and 16 (with new names) until you have taken a total of 5 sets of images (each with their YYYMMDD_HHmm time stamp name).

18. Create a text file:

/hetdata/data/ImageQuality/YYYYmmdd/CWFS/YYYYmmdd_data.txt

and record the start/stop time of each set and other details using this template:

#filename startUT stopUT wind avg(mph) wind dir struct az louvres FPS

19. When these sets are completed, you can cancel the trajectory and move on with your night. To return the CWFS to its normal state, click the "X"s in the top right corner of the Camera Control Window and the Camera Select Window. Then give control of the CWFS back to PAS/PFIP with:

syscmd -p 'CWFS_TakeControl()'

20. Ask the TO to power off the CWFS camera and retract the CWFS mirror.

21. Email Hanshin ( lee@… ) to let him know that you have done this test.