An Intriguing Way to Remove Light Pollution Gradients

[twade]

To all,

While reading the following article

http://www.space.com/scienceastronomy/091030-milky-way-panorama.html

about Axel Mellinger's 3000 frame Milky Way panoramic, I was intrigued by the following passage about his technique for removing light pollution gradients,

To fix this, Mellinger used data from the Pioneer 10 and 11 space probes. The data allowed him to distinguish star light from unwanted background light. He could then edit out the varying background light in each photograph and fit them together so that they wouldn't look patchy.

I don't know the technique he used to perform the transformations, but something similar in PixInsight Standard would be awesome.

Wade

[mmirot]

Even a overlay from the DSS images could be helpful to find points to use in a DBE model.

Max

[twade]

Max,

Even a overlay from the DSS images could be helpful to find points to use in a DBE model

Although the DSS site is dark, it is not free from light pollution, especially at lower elevations; however, using the DSS images as a first guess would be helpful.  In order to achieve a "perfect" representation of reality, the technique Axel implemented is the way to go.  There is no light pollution in space. 

Wade

[twade]

To all,

Here's a better link:

http://home.arcor.de/axel.mellinger

It describes the process a little better; however, it gives no indication how he transformed the Pioneer data to a usable form.

Wade

[Nocturnal]

Max,

Even a overlay from the DSS images could be helpful to find points to use in a DBE model

Although the DSS site is dark, it is not free from light pollution, especially at lower elevations; however, using the DSS images as a first guess would be helpful.  In order to achieve a "perfect" representation of reality, the technique Axel implemented is the way to go.  There is no light pollution in space. 

Wade

Yes, I do this for most nebula pictures these days. The biggest problem is that I first need to mosaic two or more DSS images together to get my field of view covered. But it helps quite a bit.

[twade]

To all,

I found the link that describes his technique in detail.  It is very interesting.

http://www.phy.cmich.edu/people/mellinger/research/Publications/2009/2009__PASP__Mellinger__A_Color_All-Sky_Panorama.pdf

Wade

[twade]

Sander,

The biggest problem is that I first need to mosaic two or more DSS images together to get my field of view covered

I should start doing this myself, especially for those images taken from my backyard.  My regular site is probably darker than the DSS site so it may not help when imaging from there.  With my wide-field imaging, it's going to take a lot of DSS images to cover my FOVs. 

Wade

[twade]

Sander,

Using the "North America" light pollution map in Google Earth, the Apache Point Observatory is "covered" in light pollution.  I'm not so sure this is a good survey to mimic a dark sky from in order to remove local gradients caused by light pollution.

Wade

P.S. Here's a link to the kmz file: http://bbs.keyhole.com/ubb/ubbthreads.php?ubb=showthreaded&Number=269838&site_id=1#import