The Man and Planets ChallengeAstrophotography Venus Vladimir Scheglov Armanskiy pass Magadan Russia Adaptive Optics Panasonic GH2 plasma emission laser beacon
Posted 20 May 2017 - 11:33 PM
Taken by Vladimir Scheglov on March 31, 2017 @ Magadan, Russia
After several attempts we were able to shoot my friend Alexander Korolenko during the rise of Venus. The distance between us was about 3300 m. Shot in the area of the Armanskiy pass, near Magadan. Thanks to Sergey Shibetskiy for the transport.
Camera Panasonic GH2, Rubinar 1000 mm, F10 lens. Frames from video:
2017 03 31 Человек на фоне Венеры: https://www.youtube....h?v=ozBLTxleh-8
Posted 20 May 2017 - 11:34 PM
Observing Venus (and Mars) with Adaptive Optics
Current AO Systems
Require a guide star close to the science object.
With a planet like Mars or Venus
Too big to be used as a guide star itself.
Too bright to allow a nearby star to be used as a guide star (scattered light).
e.g. Attempts to use Phobos (mag 10.4) as a guide star for Mars (mag -2.8) have not been successful.
Laser guide stars dont help.
We need an AO wavefront sensor that can work on the extended structure of the image of Mars or Venus (rather than a point source).
For Venus use the 2.3 mm cloud structure or 1.27 mm airglow (or perhaps the sunlit crescent in the visible).
For Mars use the surface albedo features.
We know this is possible because solar AO systems work on extended structure (e.g. solar granulation).
One possible solution:
Orbiting Laser Beacons for Adaptive Optics Observations of Mars and Other Planets
The use of adaptive optics to correct the effects of seeing is rapidly becoming a standard technique
in astronomical observing and is fundamental to current plans for extremely large telescopes. Adaptive optics
has proved effective for studies of small solar system objects that can be used as their own reference sources.
However, it is much harder to apply adaptive optics techniques to bright planets such as Mars and Venus, because
of the difficulty of finding a suitable reference star that is not drowned out by the intense scattered light from
the planet itself. A possible solution to the problem might be provided by current plans for laser communications
systems. For example, the Mars Telecommunications Orbiter, planned for launch in 2009, will carry a 5 W laser
to beam data back to Earth. This laser system in orbit around Mars will provide a very bright guide star, with
a magnitude ranging from 1.8 to 5.8. Such a guide star is more than bright enough for existing adaptive optics
systems and is in the range needed to support extreme AO systems, producing very high Strehl ratios. Used
in conjunction with large ground-based telescopes, this could allow studies of Mars with spatial resolutions down
to a few kilometers and allow the ground-based study of Mars to extend around much of its orbit, rather than
be limited to the time around opposition.
No need to go this far, and too extravagant. Thus, a solution nearer to the surface:
Sodium-layer Synthetic Beacons for Adaptive Optics
Using adaptive optics to compensate for atmospherically induced wavefront distortions requires a remote beacon.
In astronomical imaging the beacon can be the object of interest or a nearby bright star.
For a satellite the beacon can be a retroreflector illuminated by a ground-based laser.
Unfortunately, dim stars don't always have bright neighbors.
Synthetic beacons, generated by laser backscatter from the atmosphere, offer a solution to this problem.
These beacons are produced by using Rayleigh backscatter, or scattering by the air molecules, at altitudes below 20 km, or by using resonant backscatter from the mesospheric sodium layer at an altitude of approximately 90 km.
And maybe a simplier solution affordable for the amateur astro-imagers, by firing a 1kHz infrared pulse laser and using plasma emission to paint a beacon at 20 km altitude:
Aerial Burton 3D display projects images into mid-air
November 12, 2014
Aerial Burton has demonstrated an aerial 3D display, which can project text and images in mid-air.
"The biggest difference between our technology and other displays is, this is a screenless display. This is the only device that can show text and pictures in mid-air, without using a screen.
"Our motivation for developing this display was that we thought it would be useful in emergencies if text could be displayed in mid-air. What makes our technology different is that, when we considered how we might display such aerial text, we thought of using a phenomenon called plasma emission."
The images are constructed by firing a 1kHz infrared pulse laser into a 3D scanner, which reflects and focuses the pulses of the laser to specific points in the air. The molecules at that point are ionized, and the energy is released as photons. Aerial Burton believes that using this technology in emergencies will aid communication after a disaster, letting people know where to evacuate, or obtain food and emergency supplies.
"When we developed this as a commercial product, as you can see today, we wanted to make it transportable by car, so users can convert any suitable vehicle into a 3D display transporter, and take the display to where its needed. Wed like to achieve this by early 2015."
As well as prioritizing transportability, Aerial Burton plans to market the display overseas, to increase recognition of this technology.
Text and images projected in mid-air
Aerial Burton 3D display projects images into mid-air: https://www.youtube....h?v=GNoOiXkXmYQ
Also tagged with one or more of these keywords: Astrophotography, Venus, Vladimir Scheglov, Armanskiy pass, Magadan, Russia, Adaptive Optics, Panasonic GH2, plasma emission, laser beacon
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