Wednesday, 6 April 2016

De-rotated Jupiter

After reading a few astronomy related forums on the web, I had to realize that some planetary imagers actually do de-rotation on Jupiter image processing.
It got stuck in my head and was planning to play with the idea a bit.

Last night we were gifted in London with a superbly clear sky, so it seemed like a perfect opportunity to try this new idea out.

So I took one 5 mins long video - yes 5 minutes!! :) The golden rule is we never go over 90 sec because of the planet's rotation. But using WinJupos you can break this rule. Like everything, this method has advantages and also disadvantages too.

On the bight side it gives more details and an overall better looking to our final image. The picture below clearly represents the huge difference between a stacked image in a regular way from a 90 sec video and the one from a 5 mins long video. 

comparison of de-rotated and simply stacked images

If I have to mention any downside of this processing method is probably the less sharp edges. That is an obvious result as the planet rotates, we can only "enhance" the middle region. But I am already convinced by WinJupos, with some careful post processing it makes the end result look more pleasing, more detailed and maybe smoother too.


I cut off a 1000 frames chunk out of the whole video, ideally somewhere from the middle area and stacked it in Autostakker 2 (AS2!).
Then opened up WinJupos and made a measurement file from the stacked photo I just created form that 1000 frames.
Then open "Tools" in menu and "De-rotation of video streams"....
Open the original video and add the measurement file to the requested section. Basically that's it. You run the process and once you've got the de-rotated video, you stack it as you would normally do in AS2!. 

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