Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Where to find optical spectral datacubes?

  • Please log in to reply
2 replies to this topic

#1 jeffsuth

jeffsuth

    Sputnik

  • -----
  • topic starter
  • Posts: 30
  • Joined: 16 May 2016

Posted 07 February 2020 - 03:49 AM

I'm building a Littrow spectrograph, and playing around with the design parameters in Matlab via raytracing. I would like to find an optical spectral datacube to simulate realistic entrance rays. Does anyone know where I might find one?

 

I found a few sources for radio emissions, but nothing for visual wavelengths. I would ideally like the full 600-700nm range in high resolution (R=15000), and 350-900 in R=~2000-3000. In reality, I'd be happy with anything.

 

Any suggestions? Bonus points for M27 or something that I can eventually image and compare results against the reference.



#2 Todd N

Todd N

    Ranger 4

  • *****
  • Posts: 316
  • Joined: 07 Dec 2007

Posted 07 February 2020 - 01:34 PM

Outside my knowlege but I found this online:

 

https://www.bodkinde...ectral-imaging/

 

https://www.bodkinde...aging-products/


  • jeffsuth likes this

#3 jeffsuth

jeffsuth

    Sputnik

  • -----
  • topic starter
  • Posts: 30
  • Joined: 16 May 2016

Posted 07 February 2020 - 04:43 PM

Thanks for the links Todd, I sure like the idea of the hyperspectral camera...

 

With my low resolution datacube ask I'd like to test the feasibility of a CTIS (computed tomography imaging spectrometer). The main idea is that you spread the spectrum across 2 axes, including the -1,0,1 orders on both axes, and then each pixel becomes a sum of calculable frequencies, which you solve for. I feel like it should be extremely simple and cheap to make given it's basically a field stopped re-imager with a 2d diffraction grating in the collimated section.

 

I made a very simple Excel sheet to model the parameters to find spectral and spatial resolution and field size. I played around with some quick numbers to see what you could get on my imaging sensors with the cheap plastic gratings you can get on ebay, and it looks like I could get a R=500-1000 or so for each pixel of a 5'x5' fov.

CTIS design spreadsheet

 

Sounds pretty neat anyway. Because you get 9 images in the shot you could probably dither the data for higher spectral and spatial resolution.

 

For simulating in the raytracer, I was just going to add an image based ray source and pretend it's like an infinitely far patch of sky... then fire in the whole datacube a bunch of times and see what happens, lol! :D

 

 




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics