Venera Images, VENERA 13 fully calibrated image |
Venera Images, VENERA 13 fully calibrated image |
Sep 13 2006, 10:06 PM
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#106
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
-------------------- Space Enthusiast Richard Hendricks
-- "The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke Mother Nature is the final inspector of all quality. |
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Sep 14 2006, 08:55 AM
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#107
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Member Group: Members Posts: 593 Joined: 20-April 05 Member No.: 279 |
AndyG Here you go. Toastie! Thanks - that's more like it. Now if only it had had a video camera on it! Andy |
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Sep 14 2006, 10:51 AM
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#108
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
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Guest_DonPMitchell_* |
Sep 14 2006, 03:28 PM
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#109
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Guests |
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Sep 14 2006, 04:38 PM
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#110
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Director of Galilean Photography Group: Members Posts: 896 Joined: 15-July 04 From: Austin, TX Member No.: 93 |
AndyG was complaining that the "Real Venusian Environment" didn't come through, so I added a little bit of red to the picture to give it that "this is hot as an oven" look to it.
-------------------- Space Enthusiast Richard Hendricks
-- "The engineers, as usual, made a tremendous fuss. Again as usual, they did the job in half the time they had dismissed as being absolutely impossible." --Rescue Party, Arthur C Clarke Mother Nature is the final inspector of all quality. |
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Guest_DonPMitchell_* |
Sep 14 2006, 08:57 PM
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#111
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Guests |
AndyG was complaining that the "Real Venusian Environment" didn't come through, so I added a little bit of red to the picture to give it that "this is hot as an oven" look to it. Ah! :-) Of course the sky of Venus is actually bright orange. Everything is bathed in orange light, from a uniform hemispherical source. The cloud layer, far above, is not visible from the surface. Strong rayleigh scattering causes the terrain at a distance to be lost in a greenish-yellow haze that eventually merges with the orange color of the sky. At night, the ground at low altitudes might glow faintly red from the heat, but it is just barely hot enough for that. I'm not sure if you could see it or not. Colors from the Venera probes have never been rigorously calibrated. First of all, the radiometric response of the camera that was used before is incorrect. The spectral response of the color filtes is known, but not the relative gain correction. I have talked with Gektin about this (the camera designer), and he is searching for some data that will permit absolute calibration of the color. Namely, the spectrum of a colored calibration lamp, which was imaged during the video retrace interval. The Russians knew what to do in theory. They realized you have to solve an integral equation to recover color from the spectral responses of sensors. Bravo for them, because I don't think any American space photos have ever been processed with that sophistication. But having written that in their paper, the Russians were unable to perform the calibration, because they lacked the necessary computers. |
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Sep 15 2006, 01:33 AM
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#112
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Senior Member Group: Members Posts: 2454 Joined: 8-July 05 From: NGC 5907 Member No.: 430 |
At night, the ground at low altitudes might glow faintly red from the heat, but it is just barely hot enough for that. I'm not sure if you could see it or not. I recall that all the drop probes from the Pioneer Venus Multiprobe mission reported an increase in infrared glow before those sensors were overwhelmed. Any ideas on what it might have been? -------------------- "After having some business dealings with men, I am occasionally chagrined,
and feel as if I had done some wrong, and it is hard to forget the ugly circumstance. I see that such intercourse long continued would make one thoroughly prosaic, hard, and coarse. But the longest intercourse with Nature, though in her rudest moods, does not thus harden and make coarse. A hard, sensible man whom we liken to a rock is indeed much harder than a rock. From hard, coarse, insensible men with whom I have no sympathy, I go to commune with the rocks, whose hearts are comparatively soft." - Henry David Thoreau, November 15, 1853 |
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Sep 15 2006, 08:45 AM
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#113
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Senior Member Group: Members Posts: 3516 Joined: 4-November 05 From: North Wales Member No.: 542 |
Ah! :-) Of course the sky of Venus is actually bright orange. Everything is bathed in orange light, from a uniform hemispherical source. The cloud layer, far above, is not visible from the surface. Strong rayleigh scattering causes the terrain at a distance to be lost in a greenish-yellow haze that eventually merges with the orange color of the sky. At night, the ground at low altitudes might glow faintly red from the heat, but it is just barely hot enough for that. I'm not sure if you could see it or not. You have done so much work already to make the place look 'real' and obviously have your own mental picture of the true colouration. Why not share it with us? - perhaps day and night versions, assuming the ground glow is just visible? |
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Sep 15 2006, 10:59 AM
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#114
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Member Group: Members Posts: 688 Joined: 20-April 05 From: Sweden Member No.: 273 |
The Russians knew what to do in theory. They realized you have to solve an integral equation to recover color from the spectral responses of sensors. Bravo for them, because I don't think any American space photos have ever been processed with that sophistication. But having written that in their paper, the Russians were unable to perform the calibration, because they lacked the necessary computers. How very typical both of Russia and the US. As somebody said "as long as it can bew done with paper and pencil the russians are unbeatable". tty |
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Sep 24 2010, 08:39 AM
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#115
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Senior Member Group: Members Posts: 1083 Joined: 19-February 05 From: Close to Meudon Observatory in France Member No.: 172 |
A new work on the Venera 9 - 14 images was presented 2 days ago by well known Venus scientist Dr Ksanfomality at the European Planetary Science Congress 2010:
http://meetingorganizer.copernicus.org/EPS...PSC2010-273.pdf Unfortunately, no more details yet... BUT, having myself analysed all the Venera data available, I don't think there is much more to be seen : all features on the horizons were enhanced and the Venusian sky shown already in this UMSF Forum topic. _______________________________ [quote from the abstract with no images published] : "In 1970-80 the VENERA 9, 10, 13 and14 probes imaged the surface of Venus at landing sites. These TV photos have been published by many scientific editions, either original or processed. Since the visits of the pioneering VENERA landers, there have been steady efforts to achieve a better processing of the original images for following analysis. This paper is devoted to the description of few segments of re-processed images at their right and left hand sides, demonstrating features not noticed earlier (or ignored due to their distortion). Using this re-processing, interesting images that included both horizon and sky of Venus were produced. In the new images next mount chains or valley slopes appeared at the horizon line." |
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Sep 24 2010, 08:26 PM
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#116
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Member Group: Members Posts: 890 Joined: 18-November 08 Member No.: 4489 |
this is an old thread . has the color issue been better solved since '06
As i recall , when i did my map and colorized the radar data , there were some images redone to get the color strip on the lander "closer" to there colors . But did not take into account the effects from the pressure . and that the rocks would most likely have a slight bluish tint ( if they were on earth) In the end I gave up and just used an artistic color [attachment=22593:venus_VT...an_Vliet.jpg] |
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Oct 2 2010, 12:37 PM
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#117
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Newbie Group: Members Posts: 15 Joined: 28-November 08 From: Germany Member No.: 4498 |
A collection of surface panoramas: 180° for Venera 9 and 10, 360° for Venera 13 and 14. Reprojections are according to various suggestions on this forum. Horizon topography is probably not real, but due to inaccuracies of the reprojections (which are not strictly geometric anyway).
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Oct 6 2010, 06:06 PM
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#118
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Solar System Cartographer Group: Members Posts: 10151 Joined: 5-April 05 From: Canada Member No.: 227 |
Nice job, Sariodil. I'm not sure I agree with your connections between features near the horizon for Venera 13, but it looks good anyway. I have often thought of trying to map these landing sites, so just playing with your images I came up with these for Veneras 13 and 14. Very preliminary, but it gives an idea of what might be done eventually. The orientations of these images (where north is, in other words) is unknown.
Phil -------------------- ... because the Solar System ain't gonna map itself.
Also to be found posting similar content on https://mastodon.social/@PhilStooke Maps for download (free PD: https://upload.wikimedia.org/wikipedia/comm...Cartography.pdf NOTE: everything created by me which I post on UMSF is considered to be in the public domain (NOT CC, public domain) |
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Oct 6 2010, 07:35 PM
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#119
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Senior Member Group: Members Posts: 2082 Joined: 13-February 10 From: Ontario Member No.: 5221 |
All these re-projections and reprocessing you've accomplished here just whets my appetite for new missions. The Venusian surface has been neglected for far too long...
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Oct 8 2010, 07:44 PM
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#120
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Newbie Group: Members Posts: 15 Joined: 28-November 08 From: Germany Member No.: 4498 |
I´m not sure about the Venera 13 horizon either. When the horizon in the Camera I image came out concave in the reprojection, I thought it could be a valley floor at a lower elevation than the hills in the adjoining part of the Camera II image. On second thought, however, smooth concave valley floors are probably not what you would expect on a planet with so little erosion.
But if erosion has no part in shaping the surface, could the gaps in the hills on the horizon be the surface expression of faults? If so, one could align them with the fault azimuths on Magellan images of the landing site to narrow down the possible orientation of the panorama. |
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