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Venera-13, Venera-14 Lander Images, Images generated from raw digital telemetry
Guest_DonPMitchell_*
post May 5 2006, 07:40 PM
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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:
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ljk4-1
post May 5 2006, 07:54 PM
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FYI - There is also a thread on reconstructing Venera lander images here:

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


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and feel as if I had done some wrong, and it is hard to forget the ugly circumstance.
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Guest_DonPMitchell_*
post May 5 2006, 07:59 PM
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QUOTE (ljk4-1 @ May 5 2006, 12:54 PM) *
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.
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4th rock from th...
post May 5 2006, 08:03 PM
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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 ;-)


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Guest_DonPMitchell_*
post May 5 2006, 09:15 PM
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Ah, now I learn how to attach a picture with a thumbnail.

[attachment=5455: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:

[attachment=5456: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?
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lyford
post May 5 2006, 09:58 PM
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Hi Don - As someone who has lurked around your Soviet exploration of Venus website, it's great to see you here!


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Decepticon
post May 5 2006, 10:51 PM
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WOW!

Great work, keepers for sure. smile.gif
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RNeuhaus
post May 5 2006, 11:45 PM
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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? blink.gif

Rodolfo
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Guest_DonPMitchell_*
post May 6 2006, 02:59 AM
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QUOTE (RNeuhaus @ May 5 2006, 04:45 PM) *
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? blink.gif

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.
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Guest_BruceMoomaw_*
post May 6 2006, 03:21 AM
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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.
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RNeuhaus
post May 6 2006, 03:22 AM
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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? unsure.gif

Rodolfo
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Guest_DonPMitchell_*
post May 6 2006, 08:54 AM
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QUOTE (RNeuhaus @ May 5 2006, 08:22 PM) *
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? unsure.gif

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.
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tasp
post May 6 2006, 02:14 PM
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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.
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Guest_DonPMitchell_*
post May 6 2006, 02:46 PM
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QUOTE (tasp @ May 6 2006, 07:14 AM) *
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?!?!?!?!?!?!?


That's an interesting question. And one actual surviving Russians can answer, so I will ask them!
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tedstryk
post May 6 2006, 03:08 PM
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QUOTE (DonPMitchell @ May 6 2006, 02:46 PM) *
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).


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