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Venera Images, VENERA 13 fully calibrated image
Phil Stooke
post Oct 8 2010, 08:46 PM
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Good suggestion, but the areas covered by these reprojected images would span at most a few tens of pixels in Magellan images, and at locations in the images uncertain by many tens of kilometers, so it is very unlikely that we could do something like that.

Phil


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vikingmars
post Oct 9 2010, 07:00 PM
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QUOTE (sariondil @ Oct 2 2010, 02:37 PM) *
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).

Thanks for your contribution. You did an interesting work.
The horizon of Venera 9 should be adjusted because the lander was sitting on a slope with a 20 tilt...
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4th rock from th...
post Oct 10 2010, 12:57 AM
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It's not easy to extrapolate much from the Venera images. I'm yet to see a good geometrical correction of all the distortions.

Those "U" shaped strips are approximations, and looking at them I always have the feeling that the spacecraft is on lower ground relating to the horizon. The imaging system is similar to that of Viking, but the scanning is made at an angle in relation to the horizon.
The Venera cameras were about 2m above the surface but, as you move from the center to the edges towards the horizon, the image looks like they were taken with a lower point of view (more like Pathfinder).
All of this makes the horizon interpretation much harder. What looks like a slope might be an horizontal feature...


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Hungry4info
post Jul 21 2014, 03:22 AM
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Ted Stryk has given the Venera 9 and 10 images a bit of a makeover.
http://planetimages.blogspot.com/2014/07/s...us-in-1975.html


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Explorer1
post Jul 21 2014, 03:31 AM
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Good catch! Why did I never notice the hills at Venera 9....
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4th rock from th...
post Jul 21 2014, 09:03 AM
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Interesting results with those horizon features. laugh.gif
My only fear is that the results look too good. Easy to mistake the generated images for the actual ones...
Other than that, I still see some geometric distortion in the vertical axis. But I know from self experience that this is a difficult dataset.


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tedstryk
post Jul 21 2014, 04:06 PM
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QUOTE (4th rock from the sun @ Jul 21 2014, 09:03 AM) *
Interesting results with those horizon features. laugh.gif
My only fear is that the results look too good. Easy to mistake the generated images for the actual ones...
Other than that, I still see some geometric distortion in the vertical axis. But I know from self experience that this is a difficult dataset.

The problem is that there are less that 50,000 pixels showing the surface, and so I used somewhat distorted repeats to fill gaps in the case of Venera 9. The hills to the left can be seen at the edge of the original panorama. Many versions I've seen have the horizons so overexposed that the hills are lost. The middle hill is of course a creation created from cloned bits of the stuff on either corner...here was my thinking...there are relatively big hills on the left, and the ground is choppy on the right-hand horizon. Venera-9 is itself on a slope. So there is little chance that the horizon is flat between the two corners of the panorama. It took dozens of times going back to the drawing board before I got something that looked half-way decent. Venera 10 was much easier.
I was also trying to project it to look as though one is looking from one point rather than moving along the scene is the camera scanned...that improves some things, but creates other geometric issues.
As I said, everything is from cloned portions of the actual image data. Nothing is drawn outright. That might be an interesting experiment.


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4th rock from th...
post Jul 22 2014, 10:20 AM
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The idea of providing a "synthetic" scene is interesting.

You could to the same using elements from earth photos. As long as rock size, distribution, overall shape and composition are the same, it's a valid experiment. I'd go for that and totally skip the original imagery.


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