Is a MARS process imminent?
- Thread starter aatdalt
- Start date
We are currently working on the first version of the MultiscaleGradientCorrection tool. It will use a database with preliminary MARS data for most of the northern hemisphere and will also allow you to select custom reference images.
The complexity of this process is considerable, but if all goes as expected (and we have reasons to be optimistic), it's a matter of weeks.
The complexity of this process is considerable, but if all goes as expected (and we have reasons to be optimistic), it's a matter of weeks.
cloudbait
Well-known member
Gradient management remains, arguably, the most subjective, by-guess-and-by-golly aspect of astronomical image processing. PI has done a great job of making most other processing very mathematically (and scientifically) rigorous. I look forward to gradient management becoming a substantially objective process, as well.
That's exciting news, thank you. Looking forward to using it. Also cool to hear that custom reference images will be a built-in option. Now to sit and find out how many weeks "weeks" is.
Marcelofig
Well-known member
Great news, but what about the southern hemisphere?
We are acquiring the first layer of actual MARS data (so far, we have acquired provisional data for testing/design purposes) under strictly controlled conditions from southern Spain with two dedicated observing stations. This requires significant economic, time, and logistical investments that we can only afford for the northern sky for now.
For the southern sky, we depend on user-contributed data, which we are gathering through the MARS data upload system. Logically, user-contributed images vary largely in all aspects related to acquisition conditions, so they require a lot of work to generate coherent and compatible data sets. We are also working on this, but it requires time and additional development efforts.
With custom reference images, you'll be able to apply the MultiscaleGradientCorrection tool using your data. You'll need to acquire two images at significantly different scales: a relatively wide-field reference image and a comparatively narrow-field image that will be corrected. This additional acquisition work will allow you to implement a completely objective gradient correction task.
Just for future planning purposes, what approximate ratio between focal lengths are we talking about?
I know that this is not a definite number, but a general range of ratios would be helpful to estimate what is needed for generating ones own reference images.
CS Gerrit
I know that this is not a definite number, but a general range of ratios would be helpful to estimate what is needed for generating ones own reference images.
CS Gerrit
The original MSGR article gives some good info on that. https://pixinsight.com/tutorials/multiscale-gradient-correction/index.html
Marcelofig
Well-known member
Thanks for the answer.
I just had this question, for using MARS on objects visible from both hemispheres, for example M42, is there any difference?
danieldh206
Well-known member
I will be interesting if there is good access to the Vera C. Rubin Observatory data. The whole southern sky will be imaged every 4 to 5 nights! Although trying to process the data will be difficult if it is anything like the Subaru Observatory data. For those that don't know about the Vera C. Rubin. https://en.wikipedia.org/wiki/Vera_C._Rubin_Observatory
It will use local databases, similar to local Gaia and APASS star catalogs and XPEH ephemerides files (although completely different in structure and contents). No Internet connection will be required.
Gary Seven
Member
Great, glad to hear that. All my projects I haven't started are in a holding pattern for the next while.
I was thinking the same thing.
That, and I won't need to move to a cabin in the Canadian wilderness to get good images.
danieldh206
Well-known member
Or setup a remote pier like I did. (but it is so worth it)
cloudbait
Well-known member
I image from pristine skies, almost entirely clear of any light pollution induced gradients. But there are plenty of sources of natural gradients, that exist in the darkest of skies. No imaging location on Earth will get us away from needing gradient management tools.
danieldh206
Well-known member
After I started imaging from New Mexico, I learned how "bright" a quarter moon is. From a city it doesn't look bright, but from a B1 site I don't need any kind of flashlight while walking around.
cloudbait
Well-known member
I've seen my shadow cast by Venus. I've had gradients from zodiacal light, from gegenschein, from skyglow, from cloud layers too thin to be apparent to the eye. And, of course, from even very crescent moons.
I'm in remote Alaska and frequently deal with aurora gradients.