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  1. Data Management
  2. DM-34066

AOS rotation: test 2

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    • Improvement
    • Status: Done
    • Resolution: Done
    • None
    • ts_aos

    Description

      • Turn off all perturbations again, but this time use the cmd file to add back 1 Zernike perturbation at a time to M1 only.  I’d suggest an amplitude of maybe 250 nm.
      • Single star on the boresight.
      • For each Zernike index 4-22 (or some subset if this is too much), make a plot of the estimated Zernike coefficient vs input rotation angle.  You should get sine waves for these, with periods as follows:
      • Z4, Z11, Z22 estimated Zernikes are independent of input rotation angle.
      • Z7, Z8, Z16, Z17 period is 360 degrees
      • Z5, Z6, Z12, Z13 period is 180 degrees
      • Z9, Z10, Z18, Z19 period is 120 degrees
      • Z14, Z15, period is 90 degrees
      • Z20, Z21, period is 72 degrees
      • I predict that the above are periodic with rotTelPos, but not rotSkyPos.
      • Note that phosim injects circular Zernikes, but ts_wep is estimating annular Zernikes, so we don’t expect to recover 2*250 nm (reflection so path length changes by 500nm!) if we inject a 250 nm perturbation.

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            ksuberlak Krzysztof Suberlak added a comment - - edited

            Comparison of donuts given a single zk for a variety of `rotSkyPos`, keeping rotTelPos=0. The number in each postage stamp is the value of 'rotSkyPos' in that simulation. 

            ksuberlak Krzysztof Suberlak added a comment - - edited Comparison of donuts given a single zk for a variety of `rotSkyPos`, keeping rotTelPos=0. The number in each postage stamp is the value of 'rotSkyPos' in that simulation. 

            Comparison of donut postage stamps given a single input zk (18) for a variety of `rotTelPos`, allowing PhoSim to calculate `rotSkyPos`. As above, the number in each stamp is the value of angle input in the simulation, in that case `rotTelPos`:

             

            ksuberlak Krzysztof Suberlak added a comment - Comparison of donut postage stamps given a single input zk (18) for a variety of `rotTelPos`, allowing PhoSim to calculate `rotSkyPos`. As above, the number in each stamp is the value of angle input in the simulation, in that case `rotTelPos`:  

            In summary, as mentioned here https://lsstc.slack.com/archives/C9BEJU1T3/p1649452191399489?thread_ts=1649278238.043959&cid=C9BEJU1T3 , these tests prove that "rotTelPos in phosim_syseng4 is really just rotSpiderPos", i.e. the camera is kept at a fixed angle wrt M1M2, and the only thing that rotates due to changing "rotTelPos" is the spider. 

            ksuberlak Krzysztof Suberlak added a comment - In summary, as mentioned here https://lsstc.slack.com/archives/C9BEJU1T3/p1649452191399489?thread_ts=1649278238.043959&cid=C9BEJU1T3  , these tests prove that "rotTelPos in phosim_syseng4 is really just rotSpiderPos", i.e. the camera is kept at a fixed angle wrt M1M2, and the only thing that rotates due to changing "rotTelPos" is the spider. 

            In summary, I think we can say convincingly that this proves that there is no camera rotation imparted by 'rotTelPos', only the spider rotation. The camera is at a fixed angle wrt M1M3 assembly. This is similar to the findings of https://jira.lsstcorp.org/browse/DM-31532

            ksuberlak Krzysztof Suberlak added a comment - In summary, I think we can say convincingly that this proves that there is no camera rotation imparted by 'rotTelPos', only the spider rotation. The camera is at a fixed angle wrt M1M3 assembly. This is similar to the findings of https://jira.lsstcorp.org/browse/DM-31532 . 

            This one looks done.

            jmeyers314 Joshua Meyers added a comment - This one looks done.

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              ksuberlak Krzysztof Suberlak
              ksuberlak Krzysztof Suberlak
              Joshua Meyers
              Joshua Meyers, Krzysztof Suberlak
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