Here are images I generated from the 9-bit Venera-13 and Venera-14 data. Most of the work was spent combining three or four transmissions from the spacecraft, each with an independent set of digital noise. In some cases, scrambled regions of images were restored by recalculating the 10th parity bit, and shifting the bit stream. In particular, I resurrected a new section of the image on Venera-14 Camera II on the left side. I managed to distill out one very high quality copy of the full transmission from each of the four cameras.

Next, there is the problem of linearizing the camera response. The camera response curves published in Cosmic Research are wrong, or at least they do not extend into the darker range where a lot of the actual Venus imagery lies. You can prove they are wrong from the calibration wedges, viewed through the four different filters. Correct generation of true log response would result in wedge profiles that are exactly offset from one another. Some recent work on camera self-calibration in the computer-vision community points the way to reconstructing response curves, and when applied to the Venera images, the result is very pleasing. Round objects, like the elbow joint of the penetrometer, look round, not flat, details in shadows appears out of the blackness of the original Russian images, and some additional hills on the horizon appear out of the formerly white sky.

The full transmission consisted of several passes of the camera scanner, back and forth, across the scene. These four panoramas are combinations of up to five black-and-white images (clear filter), and a number of red, green, and blue-filter images. In Lab color coordinates, I extracted the ab channels from the red/green/blue images, and added them to the much higher quality B/W images. You can see that when making scans through the clear filter, the camera covered a wider area, the uncolored regions are just where the RGB data did not exist. Most of the blue images are black, due to a sudden drop-off in the camera response. There are probably a few areas near the bright horizon where the real RGB ratio can be extracted...a project for someone someday.

I've been too busy with my book and my company in Seattle to completely finish what I wanted to do. The color is still not correct on any Venera surface images. But the color filters in the camera were balanced with gray filters to be somewhat correct. I am awaiting one last key piece of data -- the spectral response of a color filter that was in front of the calibration wedge. With that in hand, an absolute color calibration would be possible.

Venear-13, Camera I (short program):



Venera-13, Camera II (long program):


Venera-14, Camera I:


Venera-14, Camera II:

FYI - There is also a thread on reconstructing Venera lander images here:

http://www.unmannedspaceflight.com/index.p...indpost&p=20445

Looks like his image was reconstructed from a set of Russian processed images. Not the raw data actually.

Very nice work!!! Thank you for the time you took on these images and for sharing them.

Any plans to make original CRGB data avaliable? Perhaps some super-resolution images could be created that way ;-)

Ah, now I learn how to attach a picture with a thumbnail.

Click to view attachment

Anyway, here is an example of Venera-13 Camera II, as the Russians processed it. These are their composites of multiple red, green, blue and clear-filter images. It has been linearized, but not correctly.

The actual raw transmission looks like this:

Click to view attachment

Is was sent as a 10-bit per pixel image, with one bit being parity. It's (sort-of) log of brightness. On the top (er, left), you see a calibration ramp which is scanned during the blanking interval, while the scanner is returning.

The camera is a photo multiplier tube, some fancy optics and a mechanical scanner. Don't laugh, a PMT is the absolute best light measuring device known to man, so the image quality was amazing. The mirror sat inside a 1-centimeter thick cylindrical quartz window, and inside the camera was a special lens that inverted the effect of the refraction of the window. (Russians know their optics!). Most of the pictures you see are horrible scans made off a copy of Pravda or something.

So the transmission from the lander was a long series of repeating scans like this, back and forth, with color and clear filters dropping into place. This was recorded digitally on the main spacecraft, and relayed and replayed back to Earth multiple times. From the lander to the main craft, the transmission was PCM on a phase modulated meter-band carrier. From spacecraft to Earth was sent the same, but with convolution coding. On Venera-9, the situation was similar except the orbiter transmitted the single to Earth by an N-ary PPM signal.

More than you wanted to know, right?

Hi Don - As someone who has lurked around your Soviet exploration of Venus website, it's great to see you here!

WOW!

Great work, keepers for sure.

Thanks Don to share with us your posting's pictures. Up to now, these pictures are very apreciated since these are most unique. After looking the Venusian panorama, it looks like a very cloudy day and it seems that under the lower of clouds, there is a far visibility view and the land is relatively plain, not big boulders, stones unless these rocks are flat and with layers.

I have the curiosity whereabouts how many the Venera's sondas have taken pictures on Venusian surface? It seems like no more than ten fingers?

Rodolfo

Successful Veneras in a nutshell:

Venera-3: impact with no signal
Venera-4: analyzed atmosphere, batteries ran out
Venera-5: more accurate analysis, crushed
Venera-6: ditto, crushed
Venera-7: first landing, returned surface temperature
Venera-8: landed, photometer discovered cloud depth
Venera-9: landed, first pictures, nephelometer profiles
Venera-10: landed, orbited, pictures
Venera-11: landed, orbited, detailed spectra, lightning detected
Venera-12: landed, same as V-11
Venera-13: landed, color pictures, rock analysis
Venera-14: landed, color pictures, rock analysis
Venera-15: orbited, radar imaging, IR Fourier Spectrometry
Venera-16: orbited, radar imaging
Vega-1: landed, rock analysis, cloud analysis
Vega-2: landed, rock and cloud analysis

I'm leaving out a lot of stuff, there were magnetometers, IR and UV spectrometers, polarimeters, mass spectrometers, gas chromatography, etc, etc.

And yes, 10 landings.

Oh, yes; facsimile cameras, simple though they are, can turn out very high-quality photos. Don't forget that the Viking Landers also used them.

Regaring the list of "successful" Venera landers, however: there are several decided judgment calls. Only one of Venera 7's two onboard instruments -- its temperature sensor -- worked; its pressure sensor failed. Venera 11 and 12 -- which were the first attempt at the mission later successfully carried out by Veneras 13 and 14 -- had both their sample drills and the ejectable covers on their cameras fail; only their atmospheric instruments worked. (One Russian writer reports that this was due to excessive haste and low funding of the landers' development, and that this -- along with the cancellation of Lunokhod-3 and the long delay in the launch of Luna-24 after the failure of #23 -- was all due to the fact that the Kremlin was then trying to steal a march on the US by developing a Mars sample-return mission, which turned out to be a hopeless endeavor.) And the Vega-1 lander's sample drill triggered prematurely while the probe was still descending, preventing it from making any X-ray spectral analysis -- although its gamma-ray spectrometer and atmospheric instruments worked and it properly released its cloud-layer balloon.

So, of the 10 Soviet Venus landers that survived their landings, about three can still arguably be called only "partial successes" -- and only four returned photos. Still, that's certainly a better record than their Mars missions... And it remains a fact that Venus landings and automatic dockings in Earth orbit are the two outer-space areas in which the US still hasn't matched Russia.

Don, I am sorry that I haven't clarified well enough my previous question. I wanted to know about how many pictures has all Russian sondas have taken? I seems that are as few as ten pictures in the total for all spacecrafts. Aren't it?

Rodolfo

Missions with cameras:

Luna-3
Zond-3
Luna-9 lander
Luna-13 lander
Lunokhod-1
Luna-20 lander
Lunokhod-2
Mars-3
Mars-4
Mars-5
Venera-9 lander
Venera-9 orbiter
Venera-10 lander
Venera-13 lander
Venera-14 lander
Vega-1 (Halley pictures)
Vega-2
Phobos-2 (CCD and thermoscan)

I didn't count the Mars-3 lander, which just sent back a few scanlines of noise. And of course Earth-orbiting spacecrafts with cameras are hundreds, mostly spy satellites and resource satellites.

Really appreciate the newly processed pictures!

Additionally, it is my understanding the Vega 1 and 2 landers had their cameras removed as the Halley intercept trajectory required a night time landing.

My question:

Some of the early landers had lights on them for their cameras (the lights weren't needed and were deleted on subsequent landers. Why, oh why, didn't they put lights on Vega 1 and 2 instead of removing the cameras?!?!?!?!?!?!?

Seems like an opprotunity to get some nice pictures of the surface with a light source tested and calibrated on earth would generate the most accurate color pictures possible. That would be a 'good thing', right?



I am probably missing something, but I am really wondering about this.


Also, the list of missionsis really helpful, keep in mind though, there are a very large number of launch failures not mentioned in the Soviet era literature.

That's an interesting question. And one actual surviving Russians can answer, so I will ask them!

I asked Sasha Basilevsky years ago (well, actually, I didn't ask him, I asked someone at Brown, and they forwarded my question to him and I got his reply). Basically, when the mission was designed, it was originally the next Venera mission, which morphed into the Ve-Ga (short for Venus-Halley - the Russians have no H in their alphabet). It was modified to fly by Venus and on to Halley. This was relatively late in the game, and the trajectory change left the landers no choice but to land on the night side. Adding lights would have been too much of a design change for the already built landers. It also left the balloons without a relay, which really damaged the science that they obtained (with direct to earth transmission, and with the help of the DSN, they managed to trickle back data at 4 bits/second which was so compressed, using very crude techniques by today's standards, that interpreting a lot of it is difficult, to say the least).

I just talked to Sasha, and he suggested that weight was an issue too. Vega was loaded down with experiments and fuel. It had more instruments for the Halley encounter than the other two missions combined, it had the balloon aerostats, etc.

Speaking from my own research, Vega was really focused on answering a lot of open questions about the clouds of Venus. One of the camera positions was occupied by an ultraviolet spectrometer, and the landing ring was completely covered with devices, mostly for the analysis of cloud particles.

Direct broadcast from Venus is pretty slow. That was a probelm with the Pioneer Venus landers too. Venera-11 and 12 sent about 100 times as much data as the four Pioneer landing probes, because they had to do something similar to the aerostats. Not sure why they didn't try to use the Pioneer Venus Orbiter to relay data.

It probably wasn't capable. Remember, it was the Bus that relayed the multiprobe data back, not PVO.

Recall that the PV orbiter and probes/bus were separately launched; you wouldn't want to make one dependent on the other if you could avoid it.

And in the mid-1980s, the US and USSR were going through another Cold War freeze.
They weren't very big on cooperating, though one US professor did get his dust
analyzer on the Vegas, the only US science instrument on a space probe aimed
for Comet Halley after an actual mission was canned.




I thought Venera 3 stopped transmitting just days before reaching Venus,
just like its counterpart Venera 2 did. So other than being the first craft
to impact on Venus, how could it be called a success?

Even more interesting, I thought Venera 4 was crushed by the planet's
dense atmosphere before it could land. Carl Sagan relays a very humorous
story in his 1973 book, The Cosmic Connection, regarding how Soviet
scientists tried to defend their claim that Venera 4 did reach the planet's
surface still functioning.

So are you now saying Venera 4 actually lost battery power - and therefore
communications with Earth - before being crushed? At what altitude?

Oops, Venera-3 wasn't really a success, except for its deep-space science. Well, it did hit its target though. :-)

Sagan believed Venera-4 ran out of battery power. It was rated for 100 minutes, and it transmitted for 93 minutes. Keep in mind, the atmosphere of Venus was much more dense than almost anyone expected. It doesn't seem to have reached the depth that it was designed for. The Russians never admitted this, but on Venera-5 and 6, the parachutes were made much smaller, and they went deeper. No one can be sure about this though.

Yes, I've read what Sagan and Kuz'min have had to say about this. I've been trying to gently coax Kuz'min into telling me more about that event. It was not actually unreasonable to believe Venera-4 landed, given what was expected about Venus. Radio altimeters have something called "ambiguity", so it was only really the Mariner-5 occultation data that let people figure out later that it stopped transmitting at 22 km.

With regard to mission failures, most were the result of Block-L failure -- lots of interesting planetary probes were just left in orbit. Escape stages are difficult. The Russians just started using Block-L right from the start. The Americans just waited (and waited...and waited...) for the Centaur stage to work right. It's not obvious the Russians did the wrong thing there. They managed to launch a number of big complex probes with Block-L, while the Americans were very limited by what they could do with Agena.

Getting back to the original topic for a minute, here is the true-color calibration that Brown Univerisity did some years ago:

Click to view attachment

It's based on information about the sky spectrum from the lander's spectrometer, and from information about the color of the ground, particularly from the Venera-9 lander (from its photometer, not its camera).

The real solution to the color problem is yet to be done I think. Futhermore, given the known spectral response of the color camera filters, the right way to calculate color is by solving an integral equation, the so-called inverse method. Nobody ever does that, but the original Russian papers at least mention it (Those Russians know their math!).

I do think the general appearance is roughly accurate in the top version - blue is so weak on the surface. The color under more earthlike lighting conditions is the real question.

The Soviets were actually quite explicit on the fates of Veneras 4 through 6 -- after they finally got through grudgingly admitting that Venera 4's radar altimeter was incorrectly calibrated and that Mariner 5's S-band occultation measurement of Venus' real air pressure and temperature was correct. Venera 4's hull was only designed to withstand 20 atm of pressure. In the case of Venera 5 and 6, which were already scheduled for launch in 1969 (probably on the assumption that Venera 4 might be yet another failure) at the time that they finally accepted that Mariner 5 was corrrect, they hastily thickened the hulls a little to withstand 27 atm -- which they both did. Then they promptly designed Venera 7 to settle the question of surface atmospheric conditions once and for all by thickening its hull to withstand fully 150 atm, and equipping it only with temperature and pressure sensors (like the probe that Avco had proposed for Mariner 5, in fact). The pressure sensor failed, but the combination of the temperature measurments and the time it took for Venera 7 to land allowed an indirect estimate of pressure as well, fully confrming Mariner 5's results.

So then the Soviets, certain at last, moved on to designing Venera 8 -- a probe thick-hulled enough to withstand genuine Venusian surface conditions, but as well-instrumented as the earlier Veneras (and in fact better, given its gamma-ray spectrometer and its daytime landing with a light-level photometer). Given the fact, however, that they could have built and flown this craft in 1970, their insistence on flying Venera 7 first indicates either bizarre conservatism on the the part of the Soviet program, or the fact that they didn't have enough money to build and fly Venera 8 that early.

As for the true color of the Venusian surface, Carle Pieters did an excellent article all the way back in the Dec. 12, 1986 "Science" compensating for the orange sunlight to confirm that Venus' surface is actually an inspiring shade of flat gray.

The relationship between Venera-4 and Mariner-5 was far more complex than that. To interpret the data correctly, you needed to know several facts:

1. The refractive index of the atmosphere (Venera-4's gas analysis)
2. Accurate temperature and pressure readings (Venera-4)
3. An absolute measurement of radio refraction at a fixed distance from the planet's center (Mariner-5)
4. The radius of Venus' hard surface (Kuz'min and Clark's 1964 experiment)

The fact that Venus's atmosphere was almost pure CO2 (which is highly refractive), changed a lot of things. Kuz'min quickly recalculated the surface temperature from microwave spectra (upgrading it from 600 to 700 K), and he corrected the radar measurements of the hard-surface radius.

As for what happened to Venera-4, nobody knows. I think Sagan's theory is plausible, but certainly not the dramatic macho failure mode the Russians would prefer to announce.

I refer to Pieters work above, see the posting with the color and white-light corrected panoramas. Unfortunately, they used an incorrect camera response function. The result could be improved with additional information that exists now.

Don:

Great images - it's a joy to see old data given new life!

Bob Shaw

In the upper left hand corner of DonPMitchell's Venera 13, Camera 1 (short program) photo, there appears to be the distant, blurred flank of a mountain or hill visible on the horizon... Is this an artifact or are we truly seeing a hill some distance away?

Yes its a hill in the distance. They just blew out the pixels when they stretched the contrast, in the Russian versions. It's very clearly there in the raw data.

You also see some hills in the color-filter images, in the camera-II images, because the gain blew out the pixels in the clear-filter images.

How will it really look when i am standing on the surface of Venus? Like grey or like a orange color.

It might look orange for a while but if you could stay there for a while your eyes would adjust and you would begin to find the orange increasingly less noticable.

You can see a limited similar effect by wearing 3D anaglyph specs for an extended period of time and then taking them off. If you alternately close one eye and then the next everything will appear to be alternately blue\red tinged.

Remember when they used to claim that the Venusian atmosphere
was so refracted that you could technically see all the way around
the planet and right to the back of your head (or whatever special
helmet was shielding it)?

http://www.cosmographica.com/gallery/portf...fraction%20.htm

Until, of course, your eyes melt.

On a more serious note, I've never seen the Venera landing sites pinpointed on the Magellan-based map of Venus. Anyone have any pointers? Heck, for that matter how well is our knowledge of the landing locations constrained? (I don't think Phil-o-vision's gonna help us much this time.)

-Kevin

...or your skin burns, lungs and sinuses collapse or the rest. What a human eye and brain would actually perceive on the surface of Venus is a decidedly unlikely question to be actually answered by a real human eye any time soon, if ever. It will certainly be the last proper surface humans will ever visit in person, assuming we ever get back into the habit of doing that.

Why is the refraction and the distortion of the Venus surface and atmosphere not visible in the venera images?

Quoting Don from his second or third post:

I reckon it's likely that any additional refraction effects caused by the different refractive indices of the inner and outer atmospheres was included in that bit of optical wizardry.

Other than that the only distortion would have resulted from temperature gradients in the external atmosphere whichare highly unlikely to be significant given the fairly short range covered.

Rem31 asked about the atmospheric distortion... that concept was grossly exaggerated before the Veneras landed. Now we know it doesn't really happen the way people used to suggest.

kwp asked: "On a more serious note, I've never seen the Venera landing sites pinpointed on the Magellan-based map of Venus. Anyone have any pointers? Heck, for that matter how well is our knowledge of the landing locations constrained? (I don't think Phil-o-vision's gonna help us much this time.)"

I didn't check but I expect they are marked on Ralph Aeschliman's nice map (Ralphaeschliman.com) (edit - no they are not but his maps are worth a look anyway). I'll try to find a source. I'm going to be mapping them myself in a year or two. The locations are only known to a degree or so (about 100 km)... I assume. What we have not been able to do, and never will with existing landers, is know the exact location on a specific pixel of a Magellan image. The only way we can hope to do that is with descent imaging. This is really important for any future landers, because it is crucial to know what geologic unit you are on. Our ability to interpret existing Venera data is limited because we don't know this now.

Phil

If you mean surface pictures, two landers took 180-degree black and white panoramas; two other landers took 360-degree color (or partly color) panoramas. Due to the "economical" (and strange) scan concept, though, the panoramas do not show anywhere near 360 degrees of horizon, and concentrate more on the foreground.



The Sky and Telescope Venus globe shows all (Venera, Pioneer, Vega) of the landers' locations, to whatever accuracy. I have it on my desk!

I believe the exact content of the globe is here

http://photojournal.jpl.nasa.gov/catalog/PIA03167

but the thumbnail is too small to check, and the full version is too big for me to bother with right now.

Kevin:

Don't let the humans know about *our* solid eyes! They are not yet fit to use that knowledge in a responsible fashion.

Bob Shaw

Take a look at Abdrakhimov & Bazilevsky, The Geology of Venera and Vega Landing-Site Regions. Very nice paper.

The location of Venera-8 is known to within a radius of about 300 km, the later landers to within 150 km. The first impact, Venera-3, is known to within 800 km. Up through Venera-7, the Russians were aiming at the center of the visible face of Venus, so the landers could beam a tight signal straight up.

The Vega aerostats were tracked to very high accuracy, by differential interferometry. But they drifted around to the other side of the planet, and nobody knows when the balloons failed after that.

Basilevsky thinks Venera-9 landed on the side of a canyon, within the 150km disk, given the rocky terrain seen, and the steep incline (the probe was resting on a 20 degree incline, lucky to have remained upright!).

Here are some perspective reprojections of the Venera images. The optico-mechanical camera returns an image in spherical projection. These are sectioned up and transformed into overlapping perspective views, which are then blended together in Photoshop CS2. Missing pieces of terrain are created by duplication and reversal. And of course, the left and right sides of the images are actually views of the terrain that are 180 degrees apart, so some artistic license taken here.

Click to view attachment Click to view attachment

That are great images ,about of how it will look when you are standing on Venus. With 400+ degrees celsius of course and that is (less) funny.

Yep. Venus is slightly hotter than your kitchen oven when it is in "self cleaning" mode. So a person would be reduced to a fine white ash. Oh but maybe not in a reducing atmosphere -- you might just be carbonized into a charcoal statue of yourself.

Don:

Do you have any feel for the distances to the distant parts of the Venera-13 image? And are those bits of the image 'real'? If so, that looks like it was indeed a lucky little lander!

Bob Shaw

Fabulous! Despite having spent much time staring at your other (impressively) reprocessed Venera images this is the first time I can get my head around what the view might actually look like. In the interests of verisimilitude I'd love to see the same image with an overlay indicating which portions are "artistic license" rather than simple mathematical reprojections. (Or just lacking the missing pieces of terrain.) On a similar note, how much of the horizon is really captured in those little diagonal strips across the corners of the images?

-Kevin

You can look at the original panoramas I posted earlier to see what all of the original horizon is. The rest is the same image copied or reversed.

The camera on the lander is only about 1 meter off the ground, so the features are smaller than you might think. Visibility is also quite limited in the thick atmosphere. The horizon is probably only hundreds of meters away.

Great stuff, Don.

Phil

It is like to see how the cake is cooked! in the oven

Rodolfo


Great images. Never seen before such oddies surfaces types. No much boulders, brokes stones, but just much laminated sedimentations of lavas?

Rodolfo

How are the Veneras doing at this moment? Are they still intact or are the burned.

At first, people thought they might be seeing sedimentary rock, but today it is believed the layering is volcanic ash and/or meteor-impact dust.

The Veneras are probably just sitting there today. They weren't made of anything that would melt or burn up, except some of the inside components. There doesn't seem to be much of any weathering on the surface.

GREAT!!! This is a dream coming true for me... The surface of Venus in a "human vision" perspective!
Many thanks for sharing!

These are great! Someone should do a nicely scaled comparison of Venus/Earth/Moon/Mars/Titan terrain slices now.