Voyager camera pointing information |
Voyager camera pointing information |
Jul 29 2016, 09:32 PM
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#1
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Junior Member Group: Members Posts: 54 Joined: 7-July 16 From: Austin, Texas Member No.: 7991 |
Sorry if this has been discussed anywhere but I can't seem to find much information about it - why is it that Voyager's pointing is so haphazard, as in this video of all the RAW Jupiter images - https://www.youtube.com/watch?v=bf5QJ8iFxUs?
I came across this link which says that pointing information for the images exists - http://pds-rings.seti.org/voyager/ck.html, but have also read on this forum that it's not very accurate. Would the information be useful in automatically aligning composite images and mosaics, or is it too coarse? Would it at least be useful in getting general alignments that could be refined by hand? And does anyone know why the cameras could not be pointed more accurately, or why accurate information could not be returned with the images? I assume it was some technical limitation, but just curious what it might be. |
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Aug 4 2016, 05:30 PM
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#2
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Lord Of The Uranian Rings Group: Members Posts: 798 Joined: 18-July 05 From: Plymouth, UK Member No.: 437 |
Without correction for geometric distortion, the Jupiter approach movies will look as though they were filmed underwater (I speak here from bitter experience).
I've already completed this particular video using a much more refined version of the method outlined in this clip from 2010: https://www.youtube.com/watch?v=0XjW0vZZZXw Here's a snippet of the final movie, which I can't yet release for various reasons: (But look out for it soon ) https://youtu.be/ZLSD0_-3LTM?VQ=HD1080 -------------------- |
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Aug 4 2016, 07:20 PM
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#3
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Junior Member Group: Members Posts: 54 Joined: 7-July 16 From: Austin, Texas Member No.: 7991 |
Without correction for geometric distortion, the Jupiter approach movies will look as though they were filmed underwater (I speak here from bitter experience). Yeah, I'd noticed some of the frames are like that - the edges of the planet get stretched a bit, and the ultra bright images are too large - I didn't want to use the geometrically corrected images though, at least for now, because I wanted to see what the 800x800 movies were like. But at some point I might switch to using the 1000x1000 images - I guess they would make nicer composites and mosaics also. QUOTE I've already completed this particular video using a much more refined version of the method outlined in this clip from 2010: https://www.youtube.com/watch?v=0XjW0vZZZXw That's cool with the cloud warping - QUOTE Here's a snippet of the final movie, which I can't yet release for various reasons: (But look out for it soon ) https://youtu.be/ZLSD0_-3LTM?VQ=HD1080 Nice - it's all cleaned up and stable! Looking forward to seeing the whole thing. I'd love to see a complete Voyager movie of that quality, someday. I guess it would require a lot of manual cleanup - 70k+ images - might take a while... |
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Aug 5 2016, 12:01 AM
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#4
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IMG to PNG GOD Group: Moderator Posts: 2254 Joined: 19-February 04 From: Near fire and ice Member No.: 38 |
I didn't want to use the geometrically corrected images though, at least for now, because I wanted to see what the 800x800 movies were like. But at some point I might switch to using the 1000x1000 images - I guess they would make nicer composites and mosaics also. Using the geometrically corrected images (the *_GEOMED.IMG files) makes a big difference, especially when doing mosaics. One problem with them though is that even though they have been flatfielded and cleaned up there are a few subtle blemishes and dark horizontal lines left that need to be removed by using an 'extra' flatfield if you have a low contrast scene like Saturn or some of the Jupiter closeups. Because of this I now usually use the *_CALIB.IMG files, flatfield these using 'extra' flatfields I generated and then use information from the *_GEOMA.TAB files to warp them. The result is an image that is geometrically identical to the *_GEOMED.IMG files but without the (small) 'residual' blemishes that are present in the *_GEOMED.IMG files (flatfielding the *_GEOMED.IMG files does not work well since the position of the reseau marks varies slightly with things like exposure, gain, target brightness etc.). |
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