There are 2 ways to remove coma by moving the AdSec
- using the ARGOS terminal
- using TCS GUI
How to remove coma using the ARGOS terminal
- Open an ARGOS terminal and type:
from argos.arbitrator.tcs.hexapod_controller import Coma
correction= Coma.fromNumPyArray(np.array([xxx, yyy]))
corrections are expressed in micrometers of wavefront rms. You need to use the format x.x and y.y (e.g. [1.0, 1.0]), otherwise it will give an error.
How to remove coma using the TCS GUI
- Login on obs[x] as LBTO. See UsefulLoginInfo
- Start OSSGUI right (or left)
- Click on the icon of the M2 (right or left) to open the hexapod command window
- Write down the 6 numbers in the Absolute position line: this is where you need to move back in case you get lost
- Write zero in the 6 fields of Move Relative line.
- To correct for 1um of coma surface rms along X write X=+0.982mm and RY=+102". Click on Set Reference and then on Move Relative.
- To correct for 1um of coma surface rms along Y write Y=-0.982mm and RX=+102". Click on Set Reference and then on Move Relative.
Always click on Set Reference first and then on Move Relative
NOTE: Alternatively, coma may be removed by using the "Zernike Coefficients" section of the PSF GUI. The coma coefficients are 7 and 8.
- Select the desired coefficient by clicking "Prev" or "Next".
- Click "Clear coefficients".
- Enter a value (it is relative). The value can be hundred or tenth. It requires to watch the PSF to get a feedback of the corrections.
- Click "Send".
- Click "Adjust miror" and check that the "Hexapod Platform Positions" change accordingly (x, y , RX and RY).
- 04 Nov 2014