AO-X/STX Guider use on-axis?

Discussion in 'Adaptive Optics (AO)' started by Gerard van Belle, Mar 3, 2020.

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  1. Gerard van Belle

    Gerard van Belle Standard User

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    Hi, I'm interested in the AO-X product & associated STX Guider.

    My setup is currently three PW1000's, for use at the NPOI optical interferometer at Lowell Observatory in Flagstaff, AZ. I will be equipping these units with full-up adaptive optics in the future, but I'm in need of a quick interim solution for tip-tilt, and the AO-X/STX Guider look like a possibility. In our PW1000 user's forum I saw that another PW1000 user was using the AO-X/STX Guider with good results.

    Here's the rub: my main targets are bright-ish stars (Vmag ~ 5-8) and I'd actually like to steal some of the light with a beam splitter (say, a 70/30 or something like that) to drive the STX CCD - I'm assuming that'll be where I get the most light into the STX for fastest tip-tilt tracking, rather than some random (presumably fain) off-axis nearby star. Would it be possible for me to retrofit the STX so it could be fed by such a beam splitter? (We have machine shop facilities here at Lowell for making custom parts as needed.)
     
  2. Colin Haig

    Colin Haig Staff Member

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    Thanks for reaching out. My colleague @Doug will likely weigh in on this as well.

    The AO-X can be driven by control signals from the STX camera, using a guide star hitting the STX Guider, off-axis, or with an SBIG StarChaser SC-3 off axis guiding camera.
    We have worked with the people at Innovations Foresight who have developed a dichroic beam splitter for something similar.

    Doug may be able to assist.
     
  3. Doug

    Doug Staff Member

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    I'd suggest the Innovations Foresight ONAG with an AO-X in front, and use an STF-8300M as the guide camera. The STF-8300 will be able to control the AO-X via its I2C port.
     
  4. Colin Haig

    Colin Haig Staff Member

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  5. Gerard van Belle

    Gerard van Belle Standard User

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    This looks very attractive. What kind of software is used to close the loop between the AO-X unit and the guider (say, assume a STF-8300M as recommended)? Also, do you have any sense of what sort of correction update rate with the AO-X would be possible using a brighter star (in the 30% of a Vmag ~5-8 range I noted above) for guiding?
     
  6. Doug

    Doug Staff Member

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    There are several software products that will do the job. The cameras come with MaxIm LT, which has everything you need. Also you could use the free CCDOPS software.

    With a bright enough star you should be able to do well over 10 Hz.
     
  7. Gerard van Belle

    Gerard van Belle Standard User

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    Is it possible to use a simpler guider than the STF-8300M - say, anything supported by MaxIm DL? That's a really nice camera, but for a basic test setup that will be in service for less than 12 to 18 months, it might be a bit overspec'd.
     
  8. Doug

    Doug Staff Member

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    No. Only SBIG cameras with I2C ports can control the AO unit. That is the most cost-effective option at this time.
     
  9. Gerard van Belle

    Gerard van Belle Standard User

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    Ah, I understand. Thanks! Well it's not the worst thing in the world to be compelled to buy a nice CCD camera :)
     

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