Automating Spectroscopy

[Bob Denny]

Every one of these setups is totally different except for maybe some of the Shelyak units, and even then they differ. It may turn out that every one needs its own special collection of optics, mechanics, and software. Right now I am tackling one specific setup used by Oxford University. It will NOT be able to be generalized, but it may provide me with some insight on how to tackle the problem in the future.

[Bill Goff]

Hello BoB,
I've been trying to understand how this issue might be solved for spectroscopy also. Plate solving and centering with the auto guider would be a big step in the right direction as it is the only camera that actually sees the FOV.

During workshop I attended some students were using TheSkyX and reversing the camera assignments with the auto guider camera used as the main camera to plate solve and center, then reversing them again to begin the capture and guiding.

I know this thread is an old one, but wondering if this approach or some other is available? I also note the PHD2 has some instructions about guiding on a slit, but it is not an automated process. Is guiding with PHD2 off the table for now?

Is there any approach in scripting a version of AcquireImages that might be available or is it the ACP link out to MaxIm that limits this possibility with the autoguider taking on these task?

Bill

[Bob Denny]

I have participated in a couple of failed attempts to automate amateur-type spectrographs. I have a scheme for having MaxIm flip cameras. However the big barrier is identifying the desired target star in the tiny acquisition camera field. There were other problems like a fiber that floats around in the acquisition field and needs to be "detected" to know where to put the star, a port selector that has flexure and needs to have a model to know where each port points, etc. I've heard that Shelyak is developing a new spectrograph that can be automated. We can stay tuned.

[Bill Goff]

Hi Bob,
I’d like to revisit this topic. During the recent AAVSO meeting Katherine Blundell of
https://www.globaljetwatch.net


discussed an interesting approach to this problem. She is using Prism software that allows multiple camera connections and an Optec Perseus instrument selector. The system uses one camera on the Perseus to find and center the field then rotate the Perseus to the spectroscope port for guiding and the spectral acquisition camera. The Perseus is capable of moving the mount and focuser to presets for each port for exact centering. Blundell’s system is done with the scripts and I’m sure there are a number of issues, but at a high level this seems promising.


I have two questions:
1. Is connection to Perseus possible now with ACP or might this be possible in the scripting environment? I know there’s no ACP tab for this connection.


Blundell’s system requires three camera, but she also connects to a fourth camera for doing photometry with a secondary scope on the same mount. I see the MaxIm now offers an option for multiple cameras with the Maestro approach.


2. Are you considering any adaptation for ACP having multiple instance of MaxIm running with this Maestro environment so that multiple cameras would be connected? Maestro doesn’t seem to control a secondary camera but only rely on sequence timing.

[Bob Denny]

Bill -- I had a session with Blundell where I had MaxIm doing automated camera switching etc, and it was up to her to detect which star in the acquisition camera is the one she wanted to measure (not always the brightest). She also has(had) a spectrograph which had a fiber that would migrate around in the field and thus needed to be detected. The Perseus has significant flexure issues based on its load and alt-az position to the point where it needs to be integrated with the mount so it provides flexure corrections. It "almost" worked and then she disappeared.

I have to be honest... I'm unlikely to tackle this project after a couple of aborted tries (Blundell as well as two others) all of which chewed up loads of time and ultimately failed for various reasons not under my control. This will need to be provided with a special purpose set of hardware and software. It would take exotic scripts which I would not be able to support, and probably create a continuous stream of "improvement requests" that would address one or two people. It's outside my business model, especially now where I have a mature and reliable system that provides high-quality results for what it was designed to do (acquire images for science and art), and superior support of student/public usage via the web UI.

If Blundell can show reliable automated spectroscopy, it hardly matters what software does it. It will be a major accomplishment. I would just go with it.