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Unmanned Spaceflight.com _ Venus _ Venus from Ground Based radar and other

Posted by: belleraphon1 Mar 10 2015, 11:50 AM

Image Release: Venus, If You Will, as Seen in Radar with the GBT
https://public.nrao.edu/news/pressreleases/venus-surface-gbt

Impressive.

May be awhile before we return to Venus. Perhaps we need a ground based forum for the time being.

Craig

Posted by: 4throck Mar 10 2015, 04:50 PM

Interesting indeed.
I wonder if some technique could be used to remove the double image effect?

Posted by: JRehling Mar 10 2015, 05:25 PM

QUOTE (4throck @ Mar 10 2015, 09:50 AM)

I wonder if some technique could be used to remove the double image effect?

I believe a third transmitter/receiver would definitively solve that problem, but good luck getting a massive radar facility funded for the sole purpose of improving maps of Venus.

Posted by: Gerald Mar 10 2015, 06:36 PM

A cross-eyed version:

(derived from B. Campbell, Smithsonian, et al., NRAO/AUI/NSF, Arecibo)

Posted by: belleraphon1 Mar 10 2015, 07:51 PM

Did not mean to give short shrift to Akatsuki mission.

Posted by: Phil Stooke Mar 10 2015, 08:45 PM

A third transmitter would help, as suggested, but also the same method applied at a different inferior conjunction will have the Doppler equator (the dark band) in a different location, and all the reflection effects correspondingly moved. By comparing images of different dates the ambiguity can be removed.

There is a long history of radar imaging of Venus, going back 50 years. This is by far the best single image - the bistatic method works really well - but there are many others made monostatically at Goldstone and Arecibo. The brief comments about past work in the press release don't do the subject justice. Anyhoo... there is a good basis for comparison to look for fresh lava flows or other changes. Incidentally, some past results were much higher resolution than this, so I would hope that the image we have is significantly downsampled from the real data.

Phil

Posted by: belleraphon1 Mar 10 2015, 10:09 PM

Phil...

Thanks for the comment. I had no idea ground based radar had gotten this good. When I saw the image it just blew me away.
Bodes well for long term monitoring.

Seeing the Venera images from Ted Stryk's blog http://planetimages.blogspot.ca/2015/03/venus-from-33-years-ago-and-why-we-need.html
just brought back to me how little we know about our sister world. At 62 years old wonder how much more we will know in my lifetime.

Craig

Posted by: ngunn Mar 10 2015, 10:32 PM

QUOTE (belleraphon1 @ Mar 10 2015, 10:09 PM)

When I saw the image it just blew me away.

Me too. I've not seen the radar data presented so well before, so it's a real revelation for us non-experts.

At 62 years old wonder how much more we will know in my lifetime.

Me too again. A lot I hope.

Posted by: belleraphon1 Mar 10 2015, 11:23 PM

Yeah ngunn

Blessed to have lived through the years from 1962 (Mariner 2) on... what a time. Now there are all those hot super-terrestrial exoplanets discovered
(sorry, really dislike the term SuperEarth. These are nothing like Earth). Venus can teach us so much.

Ok, done preaching, lol.

Craig

Posted by: vjkane Mar 11 2015, 07:42 PM

Has anyone seen what the resolution was for this Earth-based observation?

Posted by: Phil Stooke Mar 19 2015, 05:17 AM

I have not seen the resolution for this image, but check out this page:

http://www.naic.edu/~pradar/radarpage.html

for some images from 1999 - 2001 including a small one at 1.2 km/pixel.

Also you can poke around here... some at least are 50 pixels/degree or about 2 km.

http://pds-geosciences.wustl.edu/premgn/mg_1001/ebvenus/arecibo/

Phil