UNIVERSITY OF CALIFORNIA OBSERVATORIES / LICK OBSERVATORY |
Also, it is useful to start with the 8x lenslet array because it is a little less sensitive to errors in alignment and useful for creating a "flat" shape for the deformable mirrors for use when making the 16x control matrix.
You'll also want to look at the images from the WFS and TT cameras. From a new xterm from the user account on shimmy type the following:
Creating 8x control matrices or Creating 16x control matrices or Creating Pyramid control matrices
Additionally, once the matrices in both 8x and 16x are created, you'll need to tune the system and install the control matrices in the proper directory.
Tuning and Installing
Once you have things aligned as well as possible, we can take the
control matrix data for the tweeter (MEMS) and woofer deformable
mirrors. This procedure will push actuators and measure the
displacements of the Hartmann spots on the WFS camera and will take a
few minutes to run. Type the following commands in the shaneao
software:
If these files don't look reasonable, you'll have to try again, double
checking that all paramters were set correctly, the WFS camera had a
good background, and optical and mechanical alignment was correct.
Sometimes adjusting the amp value in the cal.calibrate command is
necessary (though the values in the example here were the best used
for the alignment in Oct 2020, the most recent time this procedure was done).
If these files look nominally OK, you can then move on to creating the
control matrices. The software to do this is on shimmy and
runs in python. Do the following commands in a user@shimmy xterm:
These files now need to be copied to real for testing.
If the performance is OK, you can optionally make a DM flat using just
the woofer to help with creating the 16x control matrix doing the following
commands:
Once you have things aligned as well as possible, we can take the
control matrix data for the tweeter (MEMS) and woofer deformable
mirrors. This procedure will push actuators and measure the
displacements of the Hartmann spots on the WFS camera and will take a
few minutes to run. Type the following commands in the shaneao
software:
If these files don't look reasonable, you'll have to try again, double
checking that all paramters were set correctly, the WFS camera had a
good background, and optical and mechanical alignment was correct.
Sometimes adjusting the amp value in the cal.calibrate command is
necessary (though the values in the example here were the best used
for the alignment in Oct 2020, the most recent time this procedure was done).
If these files look nominally OK, you can then move on to creating the
control matrices. The software to do this is on shimmy and
runs in python. Do the following commands in a user@shimmy xterm:
These files now need to be copied to real for testing.
Now we need to load the right procedures into shaneao. At the shaneao
prompt type the following commands:
Once you have things aligned as well as possible, we can take the
control matrix data for the tweeter (MEMS) and woofer deformable
mirrors. This procedure will push actuators and measure the
displacements of the Hartmann spots on the WFS camera and will take a
few minutes to run. Type the following commands in the shaneao
software:
If these files don't look reasonable, you'll have to try again, double
checking that all paramters were set correctly, the WFS camera had a
good background, and optical and mechanical alignment was correct.
Sometimes adjusting the amp value in the cal.calibrate command is
necessary (though the values in the example here were the best used
for the alignment in Oct 2020, the most recent time this procedure was done).
If these files look nominally OK, you can then move on to creating the
control matrices. The software to do this is on shimmy and
runs in python. Do the following commands in a user@shimmy xterm:
These files now need to be copied to real for testing.
Once you've determined the new control matrices are nominally
acceptable, you can move forward with image sharpening, tuning WFS
focus, etc. to get the best possible strehl on ShARCS. With luck this
will converge to a suitably high strehl for science operations.
If suitable strehl can not be obtained, you need to examine the
optical alignment of the system, mechanical stability, make sure the
procedure for creating the control matrices was properly followed,
adjust the amp parameter, etc. Note that it is not unusual to have to
run through the procedure a few times to get good control matrices.
The default location for the control matrix on real is
/data/parameterFiles/. There will already be many control matrix FITS files
in the directory, so first you'll have to save them to a back up
directory before installing the new control matrix files. In a
user@real xterm do the following:
Creating 8x control matrices
Now we need to load the right procedures into shaneao. At the shaneao
prompt type the following commands:
The last command should give you output akin to '2020-10-15', which is
the working directory into which the newly created files will be put.
Hence, that directory now needs to be created. In a new xterm for the
user account on real do the following:
Now go back to the shaneao software and setup the rtc with the
proper centroider and wave-front sensor camera rate for high signal to
noise measurements with the white light calibration source.
At this point make sure that everything is well aligned. This may
involve small adjustments to the lenslet stage, WFS X and Y stages, or
calibration source position, but be careful, as you don't want to
introduce any misalignments between the WFS camera and deformable mirrors.
There should now be H.fits and Hw.fits files in the workDir directory on real.
At this point you need to copy the data to shimmy to examine
and process it, archiving previous files as necessary.
cal.self.mode='8x'
Note that amp is the amplitude of the actuator motion during
calibration. For the tweeter this ranges from 0 to 43,000 D/A, with
the bias level set at 21500 (middle range). The delay is in seconds,
and the longer the delay for more data is acquired for each mode.
cal.saveH(workDir=workDir)
cal.calibrate(dm='woofer',amp=0.5,delay=1)
Note that the amp range for the woofer is -1 to 1.
cal.saveHw(workDir=workDir)
Now that the data are on shimmy, you can look at them with your
favorite FITS file viewing utility, e.g. ds9 and make sure they look
similar to these sample images.
ssh user@shimmy
cd observers/lgs/Calibration
mv H.fits archive/H.2020-08-12.fits
mv Hw.fits archive/Hw.2020-08-12.fits
cd parameterFiles/reconMatrix_8x
mkdir 2020-10-15
cd /data/parameterFiles/reconMatrix_8x/2020-10-15 (substitute current workDir directory)
scp H*.fits shimmy:observers/lgs/Calibration/.
This should create a number of files in the workDir directory on shimmy:
controlMatrix_8x.fits
controlMatrix_8xLGS.fits
controlMatrix_8x_dim.fits
controlMatrix_8xLGS_dim.fits
controlMatrix_8x_wls.fits
controlMatrix_8xLGS_wls.fits
It is now necessary to test the new control matrix to make sure it
works. Going back to the shaneao prompt on real do the following:
cd /u/user/observers/lgs/Calibration/parameterFiles/reconMatrix_8x/2020-10-15 (substitute the appropriate workDir date)
If the performance is not OK (loops unstable, strehl not good, etc.),
you'll want to go back to the beginning and check optical and
mechanical alignment, that you have a good background (dark)
measurement for the WFS camera, and/or using a different amp setting
in the cal.calibrate command.
gain(0,.2)
gain(.2,.2)
gain(0,.2)
Creating 16x control matrices
Now we need to load the right procedures into shaneao. At the shaneao
prompt type the following commands:
The last command should give you output akin to '2020-10-15', which is
the working directory into which the newly created files will be put.
Hence, that directory now needs to be created. In a new xterm for the
user account on real do the following:
Now go back to the shaneao software and setup the rtc with the
proper centroider and wave-front sensor camera rate for high signal to
noise measurements with the white light calibration source.
At this point make sure that everything is well aligned. This may
involve small adjustments to the lenslet stage, WFS X and Y stages, or
calibration source position, but be careful, as you don't want to
introduce any misalignments between the WFS camera and deformable mirrors.
flat()
There should now be H.fits and Hw.fits files in the workDir directory on real.
At this point you need to copy the data to shimmy to examine
and process it, archiving previous files as necessary.
cal.self.mode='16x'
Note that amp is the amplitude of the actuator motion during
calibration. For the tweeter this ranges from 0 to 43,000 D/A, with
the bias level set at 21500 (middle range). The delay is in seconds,
and the longer the delay for more data is acquired for each mode.
cal.saveH(workDir=workDir)
cal.calibrate(dm='woofer',amp=0.4,delay=1)
Note that the amp range for the woofer is -1 to 1.
cal.saveHw(workDir=workDir)
Now that the data are on shimmy, you can look at them with your
favorite FITS file viewing utility, e.g. ds9 and make sure they look
similar to these sample images.
ssh user@shimmy
cd observers/lgs/Calibration
mv H.fits archive/H.2020-08-12.fits
mv Hw.fits archive/Hw.2020-08-12.fits
cd parameterFiles/reconMatrix_16x
mkdir 2020-10-15
cd /data/parameterFiles/reconMatrix_16x/2020-10-15 (substitute current workDir directory)
scp H*.fits shimmy:observers/lgs/Calibration/.
This should create a number of files in the workDir directory on shimmy:
controlMatrix_16x.fits
controlMatrix_16xLGS.fits
controlMatrix_16x_dim.fits
controlMatrix_16xLGS_dim.fits
controlMatrix_16x_wls.fits
controlMatrix_16xLGS_wls.fits
It is now necessary to test the new control matrix to make sure it
works. Going back to the shaneao prompt on real do the following:
cd /u/user/observers/lgs/Calibration/parameterFiles/reconMatrix_16x/2020-10-15 (substitute the appropriate workDir date)
If the performance is not OK (loops unstable, strehl not good, etc.),
you'll want to go back to the beginning and check optical and
mechanical alignment, that you have a good background (dark)
measurement for the WFS camera, and/or using a different amp setting
in the cal.calibrate command.
gain(0,.2)
gain(.2,.2)
Creating Pyramid control matrices
This procedure assumes that there are good DM flat shapes created with 16x or 8x closed loops that produce good
Strehls on ShARCS images.
The last command should give you output akin to '2020-10-15', which is
the working directory into which the newly created files will be put.
Hence, that directory now needs to be created. In a new xterm for the
user account on real do the following:
Now go back to the shaneao software and setup the rtc with the
proper centroider and wave-front sensor camera rate for high signal to
noise measurements with the white light calibration source.
At this point make sure that everything is well aligned. This may
involve small adjustments to the lenslet stage, WFS X and Y stages, or
calibration source position, but be careful, as you don't want to
introduce any misalignments between the WFS camera and deformable mirrors.
There should now be H.fits and Hw.fits files in the workDir directory on real.
At this point you need to copy the data to shimmy to examine
and process it, archiving previous files as necessary.
cal.self.mode='pyr'
Note that amp is the amplitude of the actuator motion during
calibration. For the tweeter this ranges from 0 to 43,000 D/A, with
the bias level set at 21500 (middle range). The delay is in seconds,
and the longer the delay for more data is acquired for each mode.
cal.saveH(workDir=workDir)
cal.calibrate(dm='woofer',amp=0.1,delay=1)
Note that the amp range for the woofer is -1 to 1.
cal.saveHw(workDir=workDir)
Now that the data are on shimmy, you can look at them with your
favorite FITS file viewing utility, e.g. ds9 and make sure they look
similar to these sample images (see 16x H.fits and Hw.fits above, as they will look similar).
ssh user@shimmy
cd observers/lgs/Calibration
mv H.fits archive/H.2020-08-12.fits
mv Hw.fits archive/Hw.2020-08-12.fits
cd parameterFiles/reconMatrix_pyr
mkdir 2020-10-15
cd /data/parameterFiles/reconMatrix_pyr/
scp A*.fits shimmy:observers/lgs/Calibration/reconMatrix_pyr/.
cd /data/parameterFiles/reconMatrix_pyr/2020-10-15 (substitute current workDir directory)
scp H*.fits shimmy:observers/lgs/Calibration/parameterFiles/reconMatrix_pyr/2020-10-15.
This should create a number of files in the workDir directory on shimmy:
controlMatrix_pyr.fits
controlMatrix_pyrLGS.fits
controlMatrix_pyr_dim.fits
controlMatrix_pyrLGS_dim.fits
controlMatrix_pyr_wls.fits
controlMatrix_pyrLGS_wls.fits
It is now necessary to test the new control matrix to make sure it
works. Going back to the shaneao prompt on real do the following:
cd /u/user/observers/lgs/Calibration/parameterFiles/reconMatrix_pyr/2020-10-15 (substitute the appropriate workDir date)
If the performance is not OK (loops unstable, strehl not good, etc.),
you'll want to go back to the beginning and check optical and
mechanical alignment, that you have a good background (dark)
measurement for the WFS camera, and/or using a different amp setting
in the cal.calibrate command.
gain(0,.2)
gain(.2,.2)
Tuning
Installing Control Matrices for routine operations
Once you have achieved a good strehl on ShARCS, you'll need to install
the new control matrices in the default directory on real for the
real-time code to find them for routine operations.
Unfortunately the shaneao code wants some of the files named
differently than the default names. Hence, we now need to copy a few
of the files to new file names. Below are the relevant copy commands to run:
At this point the newly installed control matrices should be loaded
during routine operations instead of the old matrices that have been
archived.
Elinor
Gates