When working with Voyager and Galileo images I have found that to make the color more realistic I need to use B images instead of V. If they are not available I make synthetic B from G and V images (or even O and V). Galileo didn't carry a B filter so in that case I always need to make synthetic B. Voyager had a B filter but sometimes only V images are available. The color improvement by using B instead of V is somewhat target-dependent. For example you get a big improvement for Io, a significant one for Saturn but not a very big one for Jupiter. See my experimental renderings page for details (scroll down to "Io's color" and "Jupiter's color").

I haven't attempted Viking Orbiter color processing so I don't know how the Viking dataset compares to Voyager and Galileo and how Mars compares to Jupiter, Saturn and Io but I wouldn't be surprised if something similar applied there as well.

Bjorn: off-topic, but regarding Io's color; I believe that upper left Galileo-based image might actually be very close to "true" color. The only thing that might be slightly off are some areas that are too bluish (essentially the color variation should be smaller). A while ago I did a crude try to use VIMS spectra to get the color for some of the galileans. Its accuracy is questionable given the sheer distance the spectra were taken and also the noise problems of the spectrometer, but the result is distinctively yellow for Io. Europa and Ganymede turned out much less colorful. Here's what I got. Now, this is not to imply Europa and Galileo are whitish, the data quality drowned out their intrinsic color, but Io's yellowness still stands out and that's noteworthy.

Edit: There's also this Cassini-Galileo release that shows Cassini's view also as very yellowish, though I don't recall seeing any Cassini RGB sets for Io in the PDS so it might have been simply adjusting to the Galileo colors.

I saw your VIMS images some time ago but had forgotten about them. Here's what I get when I blur and resample my Io images:

Click to view attachment

Interestingly, the images in row 2 are more similar to your image than the images in the top row. The implication is that Io's color should be roughly intermediate between the 'Galileo color' and my 'best color' although this is almost certainly an overinterpretation of the very limited existing data.

I'm not very familiar with New Horizon's instruments but cannot but wonder if any 'VIMS-like' color observations are possible...

They said in the press conference yesterday that their plans included spectroscopy with the "highest spectral resolution ever" on the Galilean satellites, and that they'd also manage to get some imaging coverage at higher resolutions than Galileo in some spots that Galileo missed. I don't know whether that's just infrared spectroscopy or also visible. The Ralph instrument does both, though if I read it correctly there is less spectral resolution in the visible than the infrared wavelengths.

--Emily

I have redone the global view taken while the dust storm was still in progress. I think the newer version is much cleaner.

Going back to an older post on this thread, about nomenclature.

The names of albedo markings are still official for telescopic use, but it's rare (and would be confusing) to combine the albedo feature names with the topographic names on a single map.

However, virtually all of the non-crater features take their names from the old albedo feature names. Acidalia Planitia roughly coincides with Mare Acidalium, for instance. Even where this is not so obvious, careful comparison with old maps will often turn up the corresponding albedo feature. A very good guide to this is Jurgen Blunck's "Mars and its Satellites" (Exposition Press, 1982, second edition). The historical lists of old maps in it are also very useful.

Phil

Perhaps actual topographic features and gross albedo markings ought not be on the same maps. But I definitely think that some form of albedo-marking map ought to be officially recognized. As long as amateur skygazers on Earth look at Mars through their 'scopes, they ought to have the pleasure of saying that they saw Syrtis Major, or Sinus Meridiani, when they glanced through the eyepiece. Or, at the very least, have the pleasure of saying that they saw *something* they can name, as opposed to "you know, that big dark triangular feature" or "the big dark thing that looks like a claw-ended arm, right along the equator."

For me, the great reaching claw of Sinus Meridiani has always been the "face" of Mars, the look that defined the planet in pre-space age telescopic images. The fact that one of our plucky little rovers is sitting at the tip of the Meridiani claw is just cool beyond words, to me...

-the other Doug

Well, just to clarify, I mean the two sets of names are not usually combined on one map, but IAU does have official nomenclature for both albedo and topographic features. Many maps combine albedo and topo features, but they are usually only shown with the topo names. USGS has global maps of topography with and without albedo. And of course ALPO and others routinely map Mars albedo features at every opposition, since they change with time.

Phil

I have added a Phobos-2 Thermoscan pan to my site. It is a false color view, combining an "RGB" creation using thermal infrared as red, near infrared/red as blue, and a synthetic green with some VSK color data to give it a "Marsy" look. I also did a lot to correct for the variations in the Thermoscan data caused by the fact that the morning side was much darker than the evening side. I am still tweaking it, but it is nearly a finished product. I removed the shadow of Phobos, which appeared as a streak through the center of both images (because Phobos-2 was in a similar orbit to Phobos at the time), because due to the fact that the intensity of the streak varied based on the amount of time an area had been in eclipse in thermal infrared, while in visible/near infrared it was simply a matter of illumination, the color results were garish. I have posted a small version below, and hyperlinked it to a full-size view.

Ted:

Delicious! Do you make a point of letting the Russian chaps see this sort of image, or does it just leak out once on the WWW?


Bob Shaw

I have in the past, although I haven't had much contact along those lines recently.

Ted, your new page is coming along very nice! I like your new processings, very consistent!

Thanks!

I have added some new stuff. It can be accessed via this link, which is my moon page (there is also an Asteroid page, but the Stardust page is the only entry, and it is already linked to from the moon page.

Ted

I have updated my site with a new Mariner 7 page, although it is still very much a work in progress.

http://www.strykfoto.org/mariner69/mariner7.htm

Wow! I don't know if I have ever seen any of those. Thank you, Ted.

Why do they look so...impressionistic?

--Emily

Great images Ted, though I'm a little disappointed you didn't create an animation of the images in sequence. If you want me to make the animation, zip up the individual frames and I'll have a go at it... send them to mizarkey@sbcglobal.net

Note on frame RBL021013, one of the closest-in frames with Syrtis Major's tip cut off near the bottom center of the frame...

To the left of the tip of Syrtis Major is a small somewhat oval dot a few pixels across.

Photos. In transit. The first resolved image of a Martian moon.

Yes....the original version I did of that image lost it when I removed the vidicon marks. Fortunately, I noticed. The reason the images look a bit odd is that the far encounter images were sent back as analogue images, processed through a circuit that enhanced detail. As a result, the grayscale is shot to hell. I tried to bring it back. The near encounter images are also analogue, but also include digital images with only one in every seven pixels transmitted. The images I used for the Meridiani mosaic and the polar cap mosaics were created by the Mariner-7 team by calibrating the analogue images using the limited digital data, restoring the photometric data. The SPC color is an overlay created from far encounter data (there is also a lot of gap-fill from far-encounter data). While the wide angle cameras had color filters, in 1969, the primary thing they wanted was coverage, so very few frames overlap.

The analogue approach set I posted is complete. I reallly don't think it would make a great animation. There are a lot of gaps, due to the spacecraft periodically playing back images from the tape recorder so that new ones could be recorded.

To make the effect of the approach more "organic" in the more distant shots, I took the central 400 pixels, rather than centering them on Mars.

One image that really intrigues me is this one of the edge of the polar cap...seems to show gullies.

Is there metadata available on those images for when they were taken? One way to make an animation less stuttery is to select only a subset of the frames with more even spacing. It's not as detailed but it's better for the Web to have fewer frames anyway...

--Emily

Phobos. In transit. The first resolved image of a Martian moon.
Phobos

Brilliant as usual.

Ted Stryks again!

Phil

Yes, there is metadata, but I only have it in hardcopy. Another odd thing, which leads to the impressionistic quality, is that because of the nature of how the data was recorded and transmitted, it has pretty good spacial resolution, but the dynamic range and stepping is horrid. One solution many have done is to do 2x2 binning. The problem is that the spacial quality of some (though not all) of the images is such that they would lose some detail in that. The image below is an example. It is amazing how much quality variation there is from image to image.

I am working on a planetarium show about Mars exploration. While working on the Viking sequences I am creating a detailed Viking lander digital model as well as texture maps of the surroundings. Here is a reduced version of the color coverage of the surroundings of Viking 1, from camera 2, mosaiced from numerous images.

Don

Hey, that's really nice work, Don.

There's something to be said for the Viking cameras - sure, low bit depth, low res in colour - but they produced some beautiful, seamless images Great work Don.

Doug

Don, excellent work!

They really were remarkable for their time. The fact that they were 8-bit cameras that selectively converted the used portion of the dynamic range to 6 bits for transmission results in using the 6 available bits very efficiently.

The Viking lander cameras had two smallish design defects that might have improved their results, one significantly, one a larger amount.

The cameras scanned the scene with silicon photodiodes looking up at a nodding mirror which rotated in azimuth. Since ONE detector takes an entire picture or color channel, the image quality is extremely stable photometrically. However, the detector, during brief moment when it was looking at nothing (black) inside the camera housing, would periodically take a "dark current" measurement. Every 64 scans (I think) in monochrome scans, every 64/3, I think) in 3-detector color scans. This reset the dark count, but the short sample time resulted in the sampled value jumping around noticiably in low-light imaging, putting annoying vertical bands in the image that changed each dark count resampling. The defect was that the count wasn't measured and transmitted with engineering data, preventing easy and almost perfect removal of the stripe pattern.

The other defect, more significant, was that the camera had absolutely no automatic exposure adjustment capability. You pre-selected camera gain and zero-level offset, had the commands coded and sent up to the spacecraft, and waited some days or more after the exposure was set to see if you were right. Normally, it worked OK, but during the dust storm season for both landers and when northern winter ice clouds were varying illumination at the surface as cold fronts passed for Viking 2 (I think), they'd have illumination drop and badly underexposed pics, they'd adjust exposures, have the illumination brighten, and the commanded image would be unusably saturated in brighter areas or everything except actual shadows. That caused real science data loss.

Still....., Marvelous cameras.

Fascinating stuff Ed!

I'd love to know what the very first pancam - the rotating push-broom affair first proposed by Sqyures et.al. for Pathfinder - was really like - what the results might have been like.

Doug

Although 'pushbroom' cameras are grand for capturing static views I would ideally prefer the approach of capturing portions of the visual fields instantaneously in RGB. If, for instance, the first Viking surface photo could have managed a 'snapshot' rather than a gradually scanned image the white streaks at the start of the image would have appeared as the edge of a small dust cloud kicked up during the landing. Pathfinder, building up wide panoramas from many small frames, captured each view as a 'snapshot' which included dust devils in some instances.
The approach of carrying color video cameras on board future rovers is enormously exciting. The PR value of being able to capture a landing and dust devils, time lapse clouds, guysers etc. is enormous. If anything the trend of evolution of 'added value' imaging from Mars should move toward full 30 frame per second full HD video. The data transmission would be daunting but the technological trends seem to be steadily improving that aspect of the problem. There are things you need good 'temporal' and visual resolution to study.

"full 30 frame per second full HD video"

I've always wondered if you could generate intermediate images by computer, using pairs of sequential images from a rover, to create something like 30 frame/second video without the spacecraft having to transmit 30 frames/second. Something to lessen the data rate on very valuable spacecraft transmitting resources. If you transmitted, say, 15 frames/second and generated an image between each set of sequential frames, you'd have 30 frame/second video but only use half as much spacecraft bandwidth.

It would be computationally intensive, of course, but the computer resources on the ground would be so much greater than rover transmitting resources. I guess it would all depend on how much value a smoother, longer video sequence would add to public outreach.

Well Mastcam is something like 1280 x 720 up to, I think, 5fps. To be honest, I can't imagine 30fps on Mars being THAT usefull. Be it your rover moving, or something happening on the surface of Mars, not much happens in a 30th of a second

Not saying it wouldn't be awesome - but 5fps HDTV res is enough for me for now (and enough for MRO relay as well I'd guess )

Doug

The MSL Mastcam's 720p video resolution mode @10fps would generate a raw data rate of 100Mbps+ depending on how many bits per pixel it's built to produce. I suspect that since it uses a Bayer filter pattern it will actually be capturing pixels at 25% of that rate spread across the Bayer 2G:1B:1R range and interpolating back to full resolution before compression. In the end the video camera and in situ processing could produce very high quality video (720p HD level) for a cost of around 0.5 to 1 megabytes of data per second of MPEG-2 video.

MARDI is definitely also going to be capturing to MPEG-2 color using a similar 720p capture mode but at 5fps ("500 images in 100 seconds")

Can't wait.

... on the surface of Mars, not much happens in a 30th of a second

In general you are right, indeed obtaining color time lapse sequences over extended periods of lighting changes and clouds could be considered a more efficent use of such a system. High 'temporal resolution', such as is obtained bt 30FPS would be important in a minority of occasions such as the landing itself, and for dust devils or guysers, future sample return launches and such. I have shot a lot of dust devil videos and I often see motion near the base which is just captured in 30fps, which if obtained on Mars could aid in studying their dymanics. BTW, The difference between 24 and 30 FPS is obvious when seeing swift dynamic things like water sprays and splashes, whirling dust, and flames. Even NTSC resolution 30 FPS video would be useful, especially if it is compressed less. Interpolation between limited frames per second is a lot of work to perform well if there is something moving swiftly, with hand retouching sometimes required. Even things like shadows creeping along rocky surfaces are a pain using such methods.
The upcoming 10 FPS Martian surface video will be similar in frame rate to the Apollo lunar surface videos, and of incomparably better quality!

Don

But only on Tuesdays.

Well, I felt compelled to complete the Viking one color coverage so here is the camera one view, a work in progress. I am working on merging the two, and later adding detail with high res grayscale images. I really wish a DEM of the lander region existed, however years ago I drew a meter grid on acetate overlays over the large wall map editions of the panoramas using the stereo derived partial contour maps in the Viking Lander Atlas of Mars. I can create a 3D model from such material however it is quite laborious. There should be an automated way to do that.

Don

Click to view attachment

http://nssdc.gsfc.nasa.gov/database/Master...g?ds=PSPA-00335

This work was done, I believe at the Stanford AI Lab. It's digital contour data and would have to be interpolated to form a DEM. The whole dataset could be reprocessed using more modern techniques, I guess, but I'm not sure if anyone considers it that scientifically useful.

rimshot.

Don, a beautiful image! The horizon is so annoyingly close, but that's not your fault...

"...I can't imagine 30fps on Mars being THAT usefull. ..."

I'm sitting here imagining the MER rovers doing a test drive like one of the Apollo 16 astronauts did with the lunar rover while the other astronaut filmed him with the 16 mm camera set to a more or less normal film speed... rover bouncing along, maybe all wheels off the ground, throwing roostertails of dust in the air...

(Air... what air?.. oh. on the moon... YEAH. RIGHT!).

Don, that's beautiful! Thanks for sharing. I really like the overall color, very nice ballance between realistic and visually striking. Just one thought, the sky darkening introduced by the cameras on the top of the image is somewhat strange, now that we have good sky coverage from MER mosaics. What's your take on that? Did you correct the Viking images?

[quote name='mcaplinger' date='May 10 2007, 04:30 AM' post='89888']
http://nssdc.gsfc.nasa.gov/database/Master...g?ds=PSPA-00335

I beleive this refers to the Viking Lander atlas, which I obtained in my USGS days. I used the overhead maps with the fragmentary contours and meter grid to match the grid with landscape features and contours seen in perspective. This is a sample of such work I did in preparation for a shaded releif map I never finished. The entire Viking 1 stereo coverage area took months to chart out in this way.

An automated means to create meshes from stereo pairs from varied formats would indeed be useful. I can paint in gray levels assigned to the contours within each obliquely seen grid section and then rectify the thing section by section but that could take more time than I can presently justify.

Don
Click to view attachment

I have been searching for Suisei UV images of Halley, but they seem to be completely forgotten, and the raw data are nowhere to be found (in fact, I even heard that they are lost). Anybody know about it?

I have some scans, but no raw images.

I have a few scans too. I was just wondering where did the raw images go. And beside, there are no Suisei UV images on the net, it seems. The only thing I could find was this http://en.wikipedia.org/wiki/Suisei_probe plus some 2-bit scanned pdf.

I have looked at that Wikipedia article, and comparing it to what I do have, I am fairly confident that it is not a Susei image. It looks like it was taken with a small telescope with a chromatic aberration problem.

I went to CiNii, my favorite place for japanese scientific papers and found these JAXA papers:

http://ci.nii.ac.jp/cinii/servlet/CiNiiLog...d=ART0000606784

"Lyman Alpha Observations of Comet Halley by Suisei"

http://ci.nii.ac.jp/cinii/servlet/CiNiiLog...d=ART0000606972

"Halley's Comet Explorer "Suisei"

The images aren't too hot however, I imagine they are the same You already have,

They seem like poorly scanned versions of some of the images that I have. I have made a page with my Suisei images, which can be seen here: http://www.strykfoto.org/Suisei/Suisei.htm

The Apogee book, Deep Space - The NASA Mission Reports, has that book and 25 others on the attached DVD as PDF files (searchable text and embedded images) which makes it trivial to extract the images. None of these 26 books are available on-line at he NASA History Division and what with the movies and hard copy, this was the best 23 quid I've ever spent!

Last year at work I met someone who had worked on the Pioneer and Viking Lander images for NASA and explained some of the difficulties they went through to try to get decent images out of the downlinked data. Sadly he no longer has any of his notes and documents from that time.

Here's a WIP Pioneer 10 Jupiter poster. Processing was based on stacking images from different sources, computing a synthetic green channel and correcting for spacecraft motion and planet rotation. The images were placed on Jupiter disks to indicate the incomplete image coverage. I plant to progress to the dataset as possible.

Wow, the GRS really has been shrinking the last few decades! There is a noticeable difference in size between the P10 images and images today:

http://jupiter.cstoneind.com/