I have worked on sprucing up some global views of Europa from Galileo. There are a few more global views I hope to get to eventually. But the best two at nearly full phase benefited a lot.
http://img362.imageshack.us/my.php?image=europaviewsc6eh.jpg
[Moderator note: There are several more threads containing Galileo Europa images but they all contain several inactive image links. The main threads are:
http://www.unmannedspaceflight.com/index.php?showtopic=2016
http://www.unmannedspaceflight.com/index.php?showtopic=2174
http://www.unmannedspaceflight.com/index.php?showtopic=2222
http://www.unmannedspaceflight.com/index.php?showtopic=2082
http://www.unmannedspaceflight.com/index.php?showtopic=2142 ]
Wow, I do believe that bottom one is the most spectacular view I have ever seen of Europa. Well done! Is that one true color? Interesting to http://www.solarviews.com/raw/jup/europa.jpgit with what Voyager saw.
Yup. Verrrrrry good!
That Voyager view is the best color mosaic view, but the image quality of that version is poor. A bit fuzzy and with a bad color-cast.
WooHoo! My favorite LittleMoon! I love Europa.
I have worked a bit more....I am having OGB Voyager problems. To the right is the image as produced through standard processing. To the left is a version edited to try to look more like a Galileo image.
http://img364.imageshack.us/my.php?image=eursupcompare7qh.png
I just made an exciting "discovery" - well, a discovery to me...there is one more global color view in the Galileo set from the C10 orbit. I am surprised this hasn't been used more. The Color is IR-7560-Green-Violet. However, the green image clips the terminator, so that area is filled in with a synthetic green from the IR-7560 image and Violet image. The black and white image is a combination of a super-resolution image produced from the IR-9680, IR-7560, and Violet image, all of which were transmitted after being binned 2x2, and, for the areas available, the green image was then merged creating an even better product.
Ted - fabulous! Keep it up!
Phil
These can be compared with the cylindrical map that is on my website at http://laps.fsl.noaa.gov/albers/sos/sos.html#EUROPA
That map is awesome...I hve spent much time admiring it.
As for the color mosaic, I have tried many times to make it, but I have hit pitfalls. First, the lack of green data on the terminator. Second, when I try to fill it in with lower resolution data, it looks odd, since the green image is the only one sent back at full resolution. Third, the albedo patterns looked wierd, because the green filter data was used as for the grayscale. By making a super-res image from the binned imagery, I was able to prevent a great resolution drop on the terminator and was able to make a more realistic grayscale image without degrading it with low resolution input. By overlaying the green image over a synthetic green created from violet and IR data, I was able to make the end of the green image less noticeable.
The only other galileo global shot of Europa was from the e17 orbit. I have crudely matched it with other color data here...I will put more time into this someday. I also plan to eventually work on the G1 data and merge it with some other data for a global view.
Ted,
Your images are very nice as well, particularly the large gibbous view in post #1. One thing in particular I'd consider is comparing the hue and saturation realism to what I had used, namely the colors from Bjorn's map (that I may have tweaked a bit). Do you have a feel for the pros and cons of the color accuracy compared with Bjorn's? Both look pretty good to me - I wonder what new insights you have come up with. I'll reread your posts as well.
nice work on europa guys. It is so cool to see the images being properly reproduced instead of horrid stuff you still see in text books.
How about trying the same with images of Io?
I have thought of that. The only problem is that Io has much more color contrast than Europa (europa has some color contrast, but it is pretty predictable - Io's isn't). I am not sure if it would come out well or not. I may try.
Keep them coming! Europa really deserves an orbiter.
Regarding my Europa map, the color there was taken from global Voyager images only. I used these to colorize higher resolution grayscale data (mainly clear filter). The reason I used Voyager and not Galileo data was higher resolution and IIRC Galileo had not imaged Europa globally in color at the time I made the map. I don't remember whether I used OGB or OGV (probably the latter) - I'm at work and can't check it now.
I'm pretty sure the color is a bit too saturated in my map. It may too reddish as well, a common problem when the wavelength of the data used for colorizing is too short (e.g. O instead of R and/or V instead of B ).
I have been working on a much bigger Europa map (9000+ pixels in the horizontal direction) from time to time for more than two years. I have reprojected most of the high-res data I plan to use but haven't started working on the color. I plan to use Galileo images for color where possible, filling gaps (or very low-res areas) with Voyager data and/or synthetic color. I also expect to use synthetic B instead of V. The V images are more contrasty than the B images but mixing G and V should give a fairly good results (definitely better than using V only). One thing that complicates color work is Europa's photometric properties, limb darkening varies with wavelength and I prefer images as close to zero phase angle as possible.
Ted's images look fairly good, especially wrt sharpness but there are some saturation problems, caused both by saturation in the red images (this manifests itself as pinkish areas) and in all of the images in some cases (bright, white areas). I have some early 'test images' of Europa that look similar. And I should add that there is great color data at 1.4 km/pixel in the E14 data.
BTW Europa's color should be kid's stuff compared to Io. There is some information on Io's color on my experimental renderings page ( http://www.mmedia.is/bjj/3dtest/ ) and I will add more once I make my new map of Io available, I've been too swamped in data recently to update my website . In particular, it is impossible to use 'unmodified' IR7560 as red without seriously messing up the color balance.
If you consider the Galileo filters and their wavelenghts, you have:
Violet - 404 : Green - 559 : Red - 671 : IR756 - 756 : IR968 - 968
The human color vision has a peak response of:
Blue - 440 : Green - 510 : Red - 650
So to "convert" the Galileo filters in to "human colors" we can mix images from different filters to get the proper wavelenghts.
I've calculated the ratios and corresponding wavelenghts:
75% Violet + 25% Green = blue (443)
70% Green + 30% Violet = green (513)
80% Red + 20% Green = red (649)
50% IR756 + 50% Green = red (658)
20% IR968 + 80% Green = red (641)
I've tried this on two Europa images and the results look good. Saturation is low, but that's expected when you mix the color data. Also, Europa looks white through a telescope anyway ;-)
I experimented with filter mixes. Realistically, the problem is that Galileo image quality varies wildly depending on compression used. Also, it is rare to get a color mosaic without some bad gaps. But I did use similar mixes.
Bjorn: I see the problem in my large mosaic, but could you point out what you are talking about in my other images? I am not sure which spots you are referring to, and would like to know so I can try to correct the problem. Some of what you are seeing may be due to the fact that I jacked the contrast up on the posted images.
The pinkish areas are very prominent in the C10 image (the message dated yesterday at 05:29 PM), especially in the bright areas near the left limb and near Pwyll.
These are better but still a bit pinkish. I'm not sure why - now that I'm at home and can have a look at what happened when I was processing these same images a few years ago I see I also had some problems with pinkish areas, especially near Pwyll. They were less pinkish but still pinkish.
Time to try to finish that 9816 x 4908 map of Europa I have been working on for two years, I should be able to get more realistic color for that map. I have now checked and seen that my current map of Europa was colorized using OGV as I thought. This means it is probably too reddish and saturated.
It is probably an interesting idea to check if there are any Cassini RGB (or CB1-GB) images of Europa near closest approach.
If you try the CICLOPS site and use their new search feature for "Europa" a couple of nice (if small) color images will pop up.
Some "True Color" Images of Europa.
Somthing I found looking around. http://pirlwww.lpl.arizona.edu/HIIPS/EPO/gallery.html
This could bode well for life on Europa (and Enceladus?):
Scientific American, 30 September 2005
http://www.sciam.com/article.cfm?chanID=sa003&articleID=000E134A-5B19-133C-9A8E83414B7F4945
Geologists have produced evidence of abundant marine life on the earth from a
period when others say a thick layer of ice gripped the entire planet. The find lends
considerable support to one side of a scientific controversy that has been widely debated for
decades.
The hullabaloo is over a glacial period dating to about 750 million to 600
million years ago.
Experts agree about the presence of ice on the planet then--even at the
equator--but how much and to what extent is still up in the air. Theories range from a "snowball
Earth" hard packed in kilometer-thick ice to a "slush ball Earth" characterized by thin ice and
areas of open water. The range of conditions would have impacted the microorganisms present.
Thick ice would have made life difficult for plants and animals, one line of reasoning goes,
choking oxygen out of the sea and blocking sunlight needed for photosynthesis. Mass extinction
would ensue and after the thaw, give rise to an explosion of multicellular life.
Has anyone here cleaned up this picture? It one of my favorite images of Europa http://photojournal.jpl.nasa.gov/jpeg/PIA02528.jpg
WOW! Keeping that one!
Have anymore? Webpage?
So many moons and planets, so little time.. perhaps the Planetary Society will get enough money for a close inspection of Europa sometime soon.
Europa has always capture my imagination.
I even dream of swimming around its oceans!
This leads me to a kinda off topic question. Has Europa ever been in a Hollywood movie besides 2010?
Decepticon,
I don't have a website but I have contributed many maps to Calvin Hamilton's Views of the Solar System. The above Europa image is created using the map at:
http://www.solarviews.com/eng/eurmap.htm
Thanks!
Great work! I have always enjoyed your work on Views. Great to see you in this forum!
Thank you all for the time and effort put into these beautiful Europa products! Ted, your E14-based Europa color mosaic is amazing. Sorry we couldn't get you that green-filter near-terminator strip returned to Earth....
-Bob P.
Answering my own question: counting only the terrestrial and icy planets and moons, and not including any asteroids, comets or KBOs, the total surface area of the non-Earth "solid" solar system objects is roughly 281.7 million square kilometers, or about 2.2 times the total surface area of the Earth (including the oceans).
That seems low somehow.
But assuming it's correct, and assuming that an astronaut could explore 10 km^2 of surface area per day, it would take 28 million "person-days" to explore the surfaces of the moons and planets in our solar system. That sounds like steady employment well into the next century.
Here's a challenge that I hope one of you might accept. During the E12 Galileo orbit, there was a sequence of Galileo color images obtained of Conamara Chaos. Below is work by the Galileo SSI team to assemble these into color mosaics. This color imaging is enough to paint much of the famous E6 Conamara Chaos mosaic in true color (or near-true color extrapolated from 2 colors)--unfortunately we still only see this region painted by false bluish color based only on the E4 Europa albedo images. Can someone accept the challenge of painting Conamara with its true E12 color?
-Bob P.
Thank you vexgizmo for the samples, since the last one was near ir, and only covered a smaller part of the area I ended up working on two colours. Part reason was that while working on the image I noted that some stripe of the blue channel was out of aligment, seems to me it was one layer below where two others images have been pasted on top.
But not entirely certain, I adjusted that at best of my ability though. In the end we see one completely unscientific interpretation of mine.
http://img12.imageshack.us/my.php?image=e12exp6ww.jpg
A second, equally unscientific attempt at colorizing the E6 transect from your new data :
Gaw-geous!!! Are you able to colorize E6ESDRKLIN01 with this? And certainly not "my" data; Galileo's data! Well, everyone's data now
E6ESDRKLIN01...first attempt:
Just for S&G, a badly tweaked version of the 1997 false-color JPL release:
To quote:
Our good friend Arthur Clarke, who wrote of Europan life in his novels, in a letter dated 27 May 1997, described the picture as being the "most extraordinary ever received from space.......".
http://www.cf.ac.uk/maths/wickramasinghe/europa.html
Yes, and -- unfortunately -- he suggested, apparently seriously, the possibility that one of the bands in it was actually an artificial roadway mde by aliens. Alas, in his old age Arthur seems to have been possessed by the evil spirit of Richard Hoagland.
I have been trying to make (true ?) color images of Europa using mainly Galileo data. I am using red (IR756 in some cases), green and violet images. The violet images have considerably more contrast than the green images. Using Voyager images as a crude guide it seems the blue images have a contrast somewhere between the contrast in the green and violet images. Because of this I also made synthetic blue images as B=(G+V)/2.
I am attaching two preliminary versions of my images, one image using G1 data (IR756, G and V) and a C10 image (R, G, V). Images using V and synthetic blue are included. I should be able to get more realistic results in the future, the color balance is just a crude guess and it would be more accurate to use synthetic red instead of IR756. The red images have a bit higher contrast than the IR756 images so using synthetic red would be more realistic. Also it is probably not very accurate to use the exact average of green and violet as blue. A weighted average should be more accurate.
I eventually plan to use this to colorize a huge (roughly 10000x5000 pixels) global grayscale map of Europa I am working on. When complete it should be of slightly higher quality in terms of coverage than the USGS map. To colorize I need to remove limb darkening etc. because it varies with wavelength, making the color 'change' towards the limb. My biggest problem is that I do not know the wavelength-dependent photometric parameters for Europa. Does anyone know if Hapke parameters as a function of wavelength (or Galileo filter) are available somewhere ?
BTW I also did something similar (synthetic blue) for images of Io, see http://www.mmedia.is/bjj/3dtest/io/index.html for details.
Somehow the IR-G-V images look more "natural" to me than the ones with a synthetic blue channel. I find the orangish colors more natural than the pinkish ones using a synthetic blue channel.
That preference may have its roots in the Voyager imagery so one comes to expect an orange colored Europa -- not neccessarily its true color at all.
Err.. this may be stupid question (here it comes...) but if my $150 digital camera can take a true(ish) colour picture in a single take, why can't space probes? (well, at least the modern ones built with digital technology).
(this is where the image-processing experts roll their eyes and curse the ignorant noobs )
A consumer digicam usually has one CCD, and except for the Foveon CCD now being used in a few cameras, it cannot see all three colors with each hardware pixel. Instead, each pixel has either a red, green or blue single-pixel color filter in front of it. The standard design has a checkerboard pattern with 1/2 of the squares being green pixels and the rest are alternating red and blue.
When the data is read out from the CCD, smart software compares adjacent pixels and local brightness trends and makes a smart educated guess for what the missing two colors's brightness SHOULD be at the location of each pixel. It works. Pretty well. If you're not fussy.
That's why Pro-sumer video cameras often have 3 CCD chips and use special "dichroic" filters to let one color through and reflect another directly to that color's CCD. They're more sensative, since no photons are being absorbed, and each matched set of 3 pixels detects all the red, blue and green light that aren't randomly lost in reflection and transmission.
Spacecraft cameras, like Mariners, Viking Orbiters, Voyagers, Galileo and Cassini use one or two filter-wheels in front of cameras to swap a wide variety of filters in front of the single CCD, which you CAN'T do with a color-mosaic CCD like the ones in a consumer camera.
Some, like the MER camera filters split up the entire spectrum entering the cameras into fairly regularly spaced segments so a full set of narrowband MER filter images adds up to a 11 measurement spectrum of light entering the camera from violet to near infrared.
Galilleo and Cassini cameras also have narrow band filters that are specially designed to measure brightness in a narrow part of the spectrum. In their case, they measure light reflected from Saturn and Titan in bands where methane strongly absorbs, and you can use a set of methane and non-methane band images to measure the height <or depth> of clouds and hazes in the atmosphere. Cassini also has a set of polarizing filters to measure the polarized scattering of light by gasses and cloud/haze particles, which depends strongly on size and shape of cloud particles.
To take "TRUE-color" images, you have to design a set of color filters who's transmission varies with wavelength so that when combined with the transmission of the optics and wavelength dependent response of the camera CCD <or vidicon on old missions> you fairly precisely match the red, blue and green responses of "standard" color vision. To do that, you end up with a set of filters that are less ideal for scientific purposes, like estimating a surface spectrum as in the MER cameras.
MSR is planeed to have "hi-def" camera capabilities in color, and I suspect those detector/filters will be mosaic types, as in consumer cameras and camcorders. Even if color data from them won't be "full scientific grade" in quality, it will still be more useful for navigation and spotting "interesting" targets to look at closer than the monochrome hazcam and navcam images.
Good explanation, Ed. Photography is all smoke and mirrors, whether it be black and white, grayscale, color, silver halide or doped silicon.
--Bill
edstrick's explanation made me think of a question of spaceprobe construction:
Why even use filter wheels at all?
Now that 1000 x 1000 pixel sensors are so cheap, we can load probes with as many cameras as we want. Look how many the MERs have. So instead of possibly-sticky mechanical wheels, or prism arrangements (imagine a gigantic 8-prism for 8 filters!), why not just have an array of 8 separate cameras all pointing the same way, each with its own dedicated filter?
Granted, for landers or other close-up features the parallax would be unacceptable, but for planetary flyby/orbits, parallax would be too tiny to see. (Wouldn't it?) Then it could take pictures with ALL the filters all at the same time--no motion shift between them! And you wouldn't even have to worry about 8x the data coming back, because you could still transmit them sequentially, or even decide which filtered pictures are worth sending.
How come they're not being built this way now?
Exploitcorporations Did you find any global images that have not been seen yet?
Nice!
Yeah, global color views and what the Cassini folks would call "Kodak Moments" were some of the big losers to Galileo's woes.
C10 images were more intended to study the rings, but Europa happened to be there, and kind of stole the show. It is a pretty set, but is black and white.
The two C20 images are so underexposed and extremely noisy, making them almost unrecognizable. Here is the best I have been able to pull from them.
pretty map
http://news.bbc.co.uk/1/hi/sci/tech/6454039.stm
The remarkable mosaics on the "Ganymede Revisited" thread got me thinking
about what might have been done for Galileo's Europa images on UMSF.
Lo and behold, there are earlier threads that included Europa mosaics. I say that
in the past tense because if you check out threads such as "Europa's Northern
Plains" and "Thera, Thrace, and Agneor Linea," then you will see that most, if not
all, of those mosaics are gone. It appears that the host for those data may no longer
exist, as such.
Can the members of UMSF re-create some of those Europa mosaics, which, from
the comments in those threads, were impressive?
Another Phil
Exploitcorporations has a spectacular collection on her Flickr site.
Hi Phil. All of those mosaics are in reduced-scale form at the flickr link at the bottom of my posts now...the site they had been linked to was deleted in my long absence last summer. I will eventually have those dead links connected to the flickr page, and hopefully get those images up there at full size once I scrape enough change out of my sofa to get a paid account.
Here is one mosaic I really like and which I found only recently:
http://berlinadmin.dlr.de/HofW/nr/080/
Just 4 pictures assembled out of 30 taken during E19 in order to search for plumes.
Anyway, the perspective is amazing !
Marc.
It's so nice to see mosaic footprints aligning nicely in Galileo imagery. That's what a scan platform and a fast camera gives you, I guess. Were it not for forced JPEG-like compression, the imagery would have been very crisp. The PSF of the Galileo SSI camera was pretty tight and images could be sharpened nicely. Galileo may have had a lower resolution CCD than Cassini, but the image crispness more than compensated for it. It really was a capable camera...
All the more reasons to regard the loss of the HGA as catastrophic.
Take a look at the raws from the lunar flybys. Gives you an idea of what could have been done had the antenna opened.
May be this is not really new, but I just found it on the USGS planetary nomenclature site:
The big albedo features (bright plains and mottled terrains) on Europa have now official names (as Regio):
Name (LAT / LON / DIAM) :
Annwn Regio (20.0 / 320.0 / 2,300)
Argadnel Regio (-14.6 / 208.5 / 1,900)
Balgatan Regio (-50.0 / 30.0 / 2,500)
Dyfed Regio (10.0 / 250.0 / 1,750)
Falga Regio (30.0 / 210.0 / 2,500)
Moytura Regio (-50.0 / 294.3 / 483)
Powys Regio (0.0 / 145.0 / 2,000)
Tara Regio (-10.0 / 75.0 / 1,780)
I already knew about Argadnel and Moytura Regiones, but the other names seem to be quite new.
Some new crater and Lineae names have also been assigned.
Marc.
Here's my version of the Europa 14ESGLOCOL01 mosaic using all color that was available. A lot of synthetic color at places, the terminator is pretty much only green filter data. Too bad about that huge gouge of missing data at upper left.
http://farm3.static.flickr.com/2497/4182003334_ee614d4ba8_o.jpg
Color balance was roughly based on a http://i108.photobucket.com/albums/n15/ugordan/cassini_europa_blowup.jpg showing pretty much an identical vantage point. Still slightly exaggerated colors, I think.
Nice work!
Good work. I primarily stole from the G-1 mosaic to fill that nasty gap.
That is a fantastic image. It sure emphasizes the "bloodshot eye" appearance of Europa (but I have to go from memory as it has been years since I went to a college fraternity party).
Really amazing work, G. The long troughs near the terminator really stand out in this view; don't recall seeing them as well in previous global mosaics.
Merry Christmas to everyone on the site!
(It's one of the highest resolution mosaic of Europa from Galileo, with resolution around 10 m/pix horizontal. Artificially colorised by average color of this regio (Lat. -8.55;Long. 215))
^ That just made my day! Amazing view.
That is really nice. I especially like that sharp boundary between white above and dark below on the big fracture a little above center. I suspect the dark material must be sulfur compounds from Io settling on low areas of the surface, but it almost looks stratigraphic in that spot.
Little preview from Europa.
High resolution mosaic of Conamara Chaos (~12 m/pix). Image is colorized from lower resolution images (~200 m/pix)
This image is reduced in size (2×).
Wonderful!! I think this is the first time I have seen this mosaic without it being horribly saturated, and the color makes it even better. I love the pieces of ridges crossing rafts.
Every fine image from a Galilean moon that I see at UMSF makes me want to go back to Jupiter and do the Galileo mission properly, with a working HGA...
(Sigh)...me too, Emily, me too. Sure wish we'd see something like that proposed in the RFP cycles...could probably do it on a less-than-Flagship budget these days.
It would also be nice to have a few 10s of kilos of Pu-238.
OK, that's pretty super too. I need to get my hands on a copy of that book. The guy running the booth at DPS/EPSC had packed up his display copies before I had a chance to bat my eyelashes at him and wheedle it out of him. (I did have success with that tactic at the Springer booth, got me the display copy of Michael Carroll's latest book, Drifting on Alien Winds. I've *really* been enjoying that one.)
Wow - there are some substantial shadows there. How much vertical relief are we looking at on the edge of some of those....islands....rafts....Europabergs?
P
I can help with this little bit
Actually my new blog entry (planned) is about stereoscopic images from this mosaic. That mosaic has "only" supporting role (but at the end, it is better than I expected).
I think, that some cliffs are significantly more than 100 meters high and some are nearly vertical.
Little preview:
I would love to see a Galileo-2 type mission. The Galileo team did, one could argue, almost too good a job salvaging science, making the false impression that we have really done an orbital tour of the Jovian system.
I hate to burst everyone's bubble, but one of the ways they are making that flyby mission so low cost is by dropping Jupiter-system science.
Yes - and this is evident from the fact that the instruments are clearly optimized for close flybys only. For example, the camera has a field of view of 50 degrees (or something similar; I don't remember the exact number). After reading the orbiter and flyby PDFs I'd prefer flying the orbiter first, mainly because of my interest in a Galileo 2 style mission (there is no chance of a mission like that in the near future but no one knows what things are going to be like 10-20 years from now). Despite my interest in a 'Galileo 2', I think splitting the mission into an orbiter and a flyby spacecraft makes a lot of sense. The orbiter then becomes a Europa-specialized element.
One thing though: It now seems that ESA may do something 'Galileo 2-like' with JUICE (if that mission gets selected).
New stereograms (both anaglyph and cross-eye versions) from Europa (with Conamara Chaos mosaic and others):
http://my-favourite-universe.blogspot.com/2011/10/4th-5th-6th-7th-8th.html
Wow, this looks awesome, both the images/mosaics and stereograms. Do you have any idea of how accurate the stereograms are? At least they look realistic.
I have now 'discovered' that there actually is stereo coverage of Conamara Chaos but unfortunately it's not the very hi-res E12 stuff - it's E6 images from ~19000 and ~6600 km. I'll run it through my stereo software one day but I don't know when - I have a big 'queue' of close to one thousand (!) images I want to run through stereo and/or shape from shading software. Doing shape from shading might be interesting as well but a possible problem there is albedo variations. Regarding the E12 images I suspect the viewing geometry for the adjacent, partially overlapping images in the E12 mosaic is too similar for stereo but I'm going to check it.
And finally let's not forget this great stuff from Paul Schenk:
http://stereomoons.blogspot.com/2009/09/broken-land-touring-conamara-chaos.html
http://www.youtube.com/watch?v=4N6UmW3yh1A
Thanks,
Accuracy of the stereograms http://3.bp.blogspot.com/-AJ9YkLUbXBQ/Tq17o2R7e9I/AAAAAAAAAC4/aArJXoH4X4I/s0/anConamara1913b.png and http://1.bp.blogspot.com/-M4fFsMOHXJk/Tq2CBDs2AnI/AAAAAAAAADQ/q_n1OXh2iLQ/s0/anConamara1913.png is dependent on the precision of my eyes and my experience.
Stereograms are made by warping in Sqirlz Morph using manually added control points. With these images, I achieved my personal record - more than 1800 control points.
"I have now 'discovered' that there actually is stereo coverage of Conamara Chaos but unfortunately it's not the very hi-res E12 stuff - it's E6 images from ~19000 and ~6600 km."
I used image, 7513R from orbit E6. This image covers whole mosaic, so theoretically whole mosaic can be done in stereo with similar results to Fig.5/6.
"And finally let's not forget this great stuff from Paul Schenk:"
Yes, I know his masterful work, after all Paul Schenk is guru of DEM models. This is reason why I'm doing stereograms and not DEMs.
I made little comparison, with similar geometry, between stereogram from two images with ~same resolution (1900 and 1913 from orbit E12, http://3.bp.blogspot.com/-t8FwQ_QBl-w/Tq2YTnUfHeI/AAAAAAAAADk/YCMaESezVzw/s0/Conamara_an1900-1913.png) and
manually warped version (http://3.bp.blogspot.com/-AJ9YkLUbXBQ/Tq17o2R7e9I/AAAAAAAAAC4/aArJXoH4X4I/s0/anConamara1913b.png), so you can judge both versions. http://3.bp.blogspot.com/-t8FwQ_QBl-w/Tq2YTnUfHeI/AAAAAAAAADk/YCMaESezVzw/s0/Conamara_an1900-1913.png is right image and http://3.bp.blogspot.com/-AJ9YkLUbXBQ/Tq17o2R7e9I/AAAAAAAAAC4/aArJXoH4X4I/s0/anConamara1913b.png is left image.
I'm pleased, that someone has clue, how painful job this is.
Your pain is our gain!
Awesome, thanks.
To celebrate the selection of JUICE, http://planetimages.blogspot.com/2012/05/europa-from-galileo-another-take.html
Very nice image that initially confused me a lot since I'm familiar with all of the Galileo global color coverage of Europa (or so I think). When I read where the color is from things became more clear.
And there's my new desktop. Thanks, Ted!
Your welcome...now if Juno and JUICE would hurry up
I should add that I removed noise by hand. There was a lot of noise in the image, but no automated removal did a good job removing it without wrecking havoc on the little ridges.
Beautiful image, Ted!
It is from orbit E17, isn't it?
BTW, for JUICE is planned NAC camera with 5 microrad resolution.
With this camera, JUICE will obtain two times better images of Europa even from the orbit around Ganymede (and with many filters).
This is a mosaic of the Galileo I25 Europa images:
Great work! Oh, and I for some reason thought that this mosaic was much more spotty than this...wheels are turning in my head...
Wow, Bjorn, that is beautiful! Really makes me want to go through the Galilean imagery and play around. Can't wait to see the final product!
Wow, really great job ! A stupid question: is it possible to overlay color data from lower resolution color pictures or are they of too low resolution ?
Thanks again for these amazing pictures.
Marc.
That's a lovely mosaic Bjorn: it really highlights some of the very subtle European topography, particularly the arc-like 'trenches' near the terminator.
It is well known that Galileo's color coverage of Europa is severly limited. I've been processing all of the Galileo color coverage that is useful for colorizing a huge (16384x8192 pixels) simple cylindrical map of Europa I'm working on. What I'm posting here are some of the more useful images. I'm still working on the well known E14 data so a color mosaic from that is not included. There is also a single 1.2 km/pixel color observation from E12 but it is extremely noisy and I'm not sure I'll get anything useful enough from it.
Very early in its mission, during the G1 non-targeted Europa flyby, Galileo obtained the best Europa color coverage of the entire mission in terms of the number of filters used. This is a planning image that appeared on the Galileo website. All of the data was downlinked and without gaps:
Bjorn,
These are beautiful! There is one more not to forget: a color Europa mosaic on I33. Ted Stryk shows it here:
http://planetimages.blogspot.com/2005/09/i33-galileos-last-snapshots.html
Cheers,
-vexgizmo
Here is the I33 color image, the range is 1.9 million km. It's from 756 nm, green and violet. As in the G28 image in my previous post the color was probably a bit strange but here I attempted to correct it. I used the C10 color composite as a guide but I still have some doubts about the resulting color. Here the green image has been multiplied by 0.92 and the synthetic blue image by 0.98. The original images were rather blurry so the final image has been sharpened quite a bit:
I love these mosaics of Europa. I just realize that the upper image of the G7ESAPEXCR observation corresponds to the region observed by Galileo NIMS and where clay-like minerals have been detected:
http://www.nasa.gov/jpl/news/europa-clay-like-minerals-20131211.html#.UtHIpUrpz7I
A big impact structure should be localized just to the east, but no secundaries are visible.
I have never seen the SSI and NIMS data associated, may be it would be interesting to superpose them.
Regards,
Marc.
Great images, Bjorn.
I wonder if a color model of Europa could be constructed that assumes that the composition (in terms of color, not necessarily chemically), locally, is always at some point on a continuum between icy and non-icy. Then the limited set of color images could be used to model the obviously complex photometry function of both the icy and non-icy terrain, and re-render any B/W images according to that model. It seems like in the case of Europa, a model that simple wouldn't be far from the mark.
I've had fairly reasonable results in the past combining low res color (from Bjorn) and hi-res black and white as can be recalled here:
http://laps.noaa.gov/albers/sos/sos.html#EUROPA
I've been thinking of redoing this mosaic if I can easily obtain the latest 8K or even higher USGS map of Europa.
I understand the bleeding potential though. I wonder if somehow a local color table can be constructed to help with this, if you catch my drift. I'm not really that familiar with fancier methods of colorizing.
Steve
-- this is BASED on the USGS map
if all you want there is a 8192x4096 color map in my celestia add on
http://www.celestiamotherlode.net/creators/johnvanvliet/Europa_2k_4k_8k.zip
or
if you do not mind untilling the 16384x8192 color map
( it is chopped into 512x512 px. tiles)
http://www.celestiamotherlode.net/creators/johnvanvliet/VT/EuropaLevel_4P1.zip
http://www.celestiamotherlode.net/creators/johnvanvliet/VT/EuropaLevel_4P2.zip
http://www.celestiamotherlode.net/catalog/show_addon_details.php?addon_id=1176
if needed i could post a full sized image on my google drive
@JohnVV: Once again I get reminded how much this moon cries out for exploration. At least for full mapping at decent resolution.
Just imagine a surface formed by the convection by warm and colder ice!
In the areas where we got high resolution one can see some craters after all, the rate somewhat similar to Triton. Though the process that is thought to have eradicated craters on the latter is thought to have been transient yet quite dramatic.
Meaning that the less obvious multi-ring impact features on both look similar at first glance yet do so for somewhat different reasons.
So thank you for your work, including Bjorn Jonsson / scalbers of course also-it is good to have until we will have a mission to Europa.
( Since one orbiter for Triton is not even in the pipedram stage - unless we make a collective effort here to hijack BepiColombo. )
An approximately true color composite from 756 nm, green and violet. This is from images obtained during the E12 orbit.
Wow, impressive. I know what you had to work with.
Beautiful result for such noisy data. I'm looking forward to your map of Europa!
Conamara Chaos revisited
Conamara Chaos was particularly well observed by Galileo. Others (especially machi) have posted great versions of the E12 hi-res images so here I'm concentrating on the E6 images plus the E12 color images. Here is a 2x3 mosaic from a range of 19000 km. It shows all of Conamara Chaos below the big "X" feature:
Lovely work! I'll also add that the shapes of Galileo mosaics are sort of a signature.
Thanks for sharing...what a wonderful tour of jigsaw junction...
NASA has released an exquisite new version of http://www.jpl.nasa.gov/news/news.php?feature=4386 along with a nice promo video for exploring it.
It is a pleasant surprise to see this released after all these years. This is a very high quality mosaic, the best version from these particular source images that I have seen. A very 'clean' image and the color channels are perfectly aligned (I sometimes need to warp indvidual color channels slightly to get rid of small 'residual' alignment errors when processing color images). The color isn't as realistic here as in Ted's version though since the red channel is from near-IR images and this is not corrected for (at least not fully).
For comparison, here is a test render from a 20000x10000 pixel true color global map I'm working on. It's shaded using a slightly modified Hapke function:
One by-product from the 20000x10000 global map of Europa I'm working on is that I now have a global true color map from all of the useful color images that have a resolution ranging from ~1.2 km/pixel to ~15 km/pixel and this can be used to colorize clear filter images and mosaics. Here is a colorized version of the I25 mosaic in http://www.unmannedspaceflight.com/index.php?showtopic=1300&view=findpost&p=198922. The color is mainly from the C9 global image but a bit also comes from G2.
Gorgeous, Bjorn.
Speechless
Today, it seems that NASA is at last committing to flying a mission (probably Europa Clipper) to Europa after years of studies. By a strange conincidence, on this same day I may have finally finished the 20000x10000 pixel map of Europa I've been working on for almost 2 years (!) (but with major breaks to do several smaller projects). All that remains is to check for images I might have overlooked that I should have included in the map (I don't expect to find any). The map should include almost every image down to a resolution of ~200 m/pixel plus a selection of several higher-res images.
Here is a 4000x4000 pixel test render showing the hemisphere with the best imaging coverage, including a pole-to-pole strip left of center at higher resolution than most of the map.
Desktop'd as usual, Bjorn.
Not much else to say... fantastic as always.
No, not all of the map has this resolution. This north-south strip is from Galileo's ~200 m/pixel regional mapping which covers a relatively small part of Europa (probably most/all of Europa would have been imaged at this resolution or better had Galileo's HGA worked). In addition to this N-S strip there are several more areas at similar resolution but most of the map comes from images with a resolution of ~1.5 km/pixel. There are also areas where the source image resolution is lower though - only 4-15 km/pixel.
The map's size (20000x10000) translates into slightly better than 0.5 km/pixel resolution where the source data allows.
A mighty congratulations are in order, Bjorn! The culmination of a two-year project of this magnitude is something to be celebrated, and I hope you get the recognition and plaudits that this achievement so richly deserves.
Ian.
The full resolution version is pretty amazing -- someday it would be really nice to have a Google Earth version, like we have for Mars. A lot of details pop-out which I hadn't dwelled on previously. There are a scattering of large berg-like features, almost like boulders lying partially submerged in the surface; if we posit the thin ice shell model, these may arguably be spots where the shell has doubled-up (stacked one layer on another). I'm out of touch with Europa research, but it seems like someone ought to have studied these in depth, perhaps modeled and measured their displacement of the surrounding surface, perhaps established whether they are in hydrostatic equilibrium. Neat stuff.
True masterpiece Bjorn!
It's really pity that we haven't good topography data. It would be really tempting to combine your excellent map with some nice topography data.
Hopefully it will be possible some 20 years later with data from new Jupiter system missions.
Beautiful work, Bjorn! That may be the smoothest looking global rendering of anything from Galileo data I have ever seen.
My brand-new 20000 x 10000 pixel map of Europa can now be seen here: http://www.planetary.org/blogs/guest-blogs/2015/0218-mapping-europa.html
This is by far the biggest image processing project I have ever undertaken in terms of time and number of images (but not complexity). I now have a big directory tree associated with this image processing project; it consists of about 50 GB in 2500 files and 135 folders (!). A lot of it is temporary stuff though that can be deleted.
Please correct me if I'm wrong, but I thought that the hemispheric color asymmetry was thought to be due to the leading hemisphere being subjected to the brunt of Jupiter's radiation belt as the moon orbits thus causing decomposition of volcanic effluent deposits from Io (which aren't subjected to that on the trailing hemisphere & therefore persist.)
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