View Full Version : What do you get for 3 billion pixels?


Jacob Mason
May 21st, 2006, 07:07 AM
What do you get for 3 billion pixels?
"Sky Movies"
A powerful new telescope that will image the entire sky every three nights will be located in Chile, officials have announced. If it receives the required funding, the telescope is expected to begin operating in 2012.
...
The telescope will use a digital camera with 3 billion pixels to image the entire sky across three nights, producing an expected 30 terabytes of data per night. This will allow astronomers to detect objects that quickly change their position, such as near-Earth asteroids, or their brightness, such as supernovae.
"It surveys a larger area than ever surveyed before, and it does it repeatedly," Sweeney told New Scientist. "So it has an opportunity to get movies where the frames are a few days apart."
This should help astronomers discover dim objects as they glide through the outer solar system. It should be able to detect Earth-sized planets more than 10 times farther from the Sun than Pluto is, testing controversial theories that predict a dozen or so Earth-sized worlds were scattered out to such distances during the solar system's youth.
Source of article: NEW SCIENTIST SPACE (http://www.newscientistspace.com/article/dn9200)

Mike Tesh
May 21st, 2006, 08:42 PM
Hmm. Makes me wonder what the resolution of the Hubble Telescope is.

Stu Holmes
May 21st, 2006, 11:07 PM
Hmm. Makes me wonder what the resolution of the Hubble Telescope is.Mike - I think it's actually less than 1Megapixel.

HST has got various imaging devices on it, picking up different wavelengths of EM radiation, but, rather like the Mars Rovers Spirit and Opportunity, at the time everything was designed, the emphasis was on VERY high quality sensors and very impressive light-gathering capability rather than ultra-resolution. In fact res is really rather low compared to current consumer devices but you only have to se the images to know what great imaging sensors/algorithms they use.

Sensors on Mars rovers main cameras are also only I think 1megapixel, designed and built I think by Dalsa Corporation. No dead-pixels, very good dynamic range, very good in low-light, rather necesaary as Mars is a loooong way from the Sun, very little light, but not much in the way of atmosphere either.
Great shots.

Check this out: Hubble Space Telescope shot of some of the oldest Galaxies known (viewed obviously as they were hundreds of millions of years ago) :
http://upload.wikimedia.org/wikipedia/commons/2/2a/Hubble_Ultra_Deep_Field_Black_point_edit.jpg
Every point of light that's not a pure POINT is basically a galaxy, a bit like own own Milky Way. Each galaxy has billions of stars. Think what you're looking at !!

and a classic HST image, really stunning shot of Eagle Nebula:
http://imgsrc.hubblesite.org/hu/db/1995/44/images/a/formats/web_print.jpg

(better res) :
http://imgsrc.hubblesite.org/hu/db/1995/44/images/a/formats/full_jpg.jpg

Mike Tesh
May 22nd, 2006, 12:22 AM
Yeah I googled it and ran across something that said 800x800 pixels for resolution, but I didn't want to believe it was that low. And the way it was written wasn't that straight forward. But I guess it's probably true.

I read an article not more then two years ago that said nasa was still using power PC processors from the 1990's. They like to bet on what's proven rather then what's new. Makes sense. But I also remember hearing years ago that the Canon XL1 was approved by Nasa. I don't know what for though.

Balazs Rozsa
May 22nd, 2006, 05:44 AM
The Hubble Space Telescope has several instruments with various resolutions. In 2002 they installed the ACS (Advanced Camera for Surveys) which contains among other things the Wide Field Camera with 2048×4096 CCDs. In another (maybe older?) camera they were using or are still using four 800x800 CCDs combined together to form one 1600x1600 image.

Don Blish
May 22nd, 2006, 05:39 PM
Before you think NASA is terminally conservative in what they put up, you have to realize most of our small feature size chips wouldn't last an hour under hard radiation in space. Apparently just one cosmic ray is just a buldozer of damage so special designs are needed to somehow drain off the garbage.

Wayne Morellini
May 22nd, 2006, 07:25 PM
Yeah I googled it and ran across something that said 800x800 pixels for resolution, but I didn't want to believe it was that low. And the way it was written wasn't that straight forward. But I guess it's probably true.

That is what the Telescope is for, a zoom ;).

I read an article not more then two years ago that said nasa was still using power PC processors from the 1990's. They like to bet on what's proven rather then what's new. Makes sense. But I also remember hearing years ago that the Canon XL1 was approved by Nasa. I don't know what for though.

I think they might have just stop using the RTX Forth microprocessor from the 80's (a highly efficient device). They are all radiation hardened, and the processor choices allow for chips with larger features, as just was said.