Depends which telescope. It's not unheard of now to have 10 or more GB by the end of a run with multi CCD camera these days.
I take images with boring small cameras so I get about 500 MB worth of data a night.
With MOSAIC on Kitt Peak (a 6 CCD system) the average night worth of data is about 13.5 GB. Too many nights and you need lots of tapes or lots of compression.
There's a bunch of astro people from Arizona who read- I'm just a misplaced Arizona person working for SIRTF at Caltech.
And as to the tapes- I shutter to think what will happen when SIRTF launches- one observation with MIPS pukes out 80 GB of raw and processed data plus masks. Downlinking all that data via the DSN is going to be a cow. Thankfully I'm applying to grad schools next year so I don't have to deal with it that much!
I'm glad people got out of Stromlo- news is that there was a visitor there from Canada who was asleep and had less than 5 minutes to haul out of there.
What I think is the most impressive quote from the Stromlo emails I've seen lately:
"The telescopes are all still "hanging" on their mounts, but are not recoverable. The 50" looks like it is parked, but the lower end of the mount is melted and the mirror is a pile of goo on the floor, the Yale lens is on the floor, and the 74" mirror is damaged far beyond repair. "
The amount of heat needed to flash melt a 50" diameter piece of glass that was probably about a foot thick is impressive and ungodly at the same time. . .
You know the whole backup thing at the 90 inch only works if you remember to bring tapes up with you (which I forget on a regular basis but you know I'm a closet blonde). I just sftp my data back to multiple computers back at Steward to take care of the problem:0
The KPNO system is very nice- the Save the Bits archive makes multiple tapes of the data that get stored in the 4 meter and down in town and data gets ftp'd down to one of the NOAO Tucson servers as well. So it's on hard drive in multiple places as well as on tape in multiple places as well.
As to Stromlo- somebody brought down all the backup tapes to Canberra on Friday (the day before the fire) so most of the data was saved.
Unfortunately though a lot of us astro people are going to suffer in the near future when DAT drives stop being the best way to store our data. ..hell I have a desk drawer of DAT and DLT tapes as well as CD ROMs with data right now!
What? Hello, Thornton has become what people in Colorado hate- urban sprawl. . .
That said. ..yes IKONOS makes pretty pictures but the fact that Lockheed had the technology lets you know they had done it before for someone else- namely the US military. Scary enough that I can get 1 meter resolution images off the internet but the resolution is infinately better in military satellites with adaptive optics. . .
1- I am an astronomer so I wouldn't pay at all, I'd just apply for time through CalTech which is where I work for SIRTF
2- While whomever pays for this will get a spiffy tour of the telescopes will probably wind up in the control room at Waimea which is not on the mountain. Why? Because generally astronomers are out of shape or get loopy at altitude. The way to minimize stupid mistakes is to only let the operators move the telescope and tweak the instruments and keep the astronomers down near sea level. That said I've done a few dumb things at telescopes myself when it was 3 am and I just wanted to go to bed at telescopes at only 7000 ft altitude. . .
Um you guys didn't note at the bottom of their discussion of their journals that publication is not free- instead like other journals they charge you page fees to get your work printed! This is like all other journals where a lot of the grant money goes to publication (Astrophysical Journal charges $150 per page for the print edition and $120 per page for the electronic edition).
This is why we should do away with journals and expand arxiv (xxx.lanl.gov)!
Ahh gee read the article-
VPL is for the theory end- it's where scientists can model planet formation for both our solar system and others. Part of the purpose of VPL is to be able to model the formation of our own solar system so we can greater understand other solar systems and solar systems with brown dwarfs.
TPF- Terrestrial Planet Finder is the telescope that will come after SIRTF and NGST (now know as the James Webb Space Telescope).
Also, Vikki is not the "creator" of anything- she is the Principal Investigator for the NASA Astrobiology Institute and she is also on the Science Working Panel for TPF.
As an astronomer who studies Cassiopeia A-
I will admit that this picture doesn't really say alot to the public other than "Hey pretty picture" and it is NOT a dying star! The reason it is of interest is because the Chandra Space Telescope first saw evidence of a point source at Cas A's center indicating a remnant of the supernova explosion that hasn't been seen in any other wavelengths. Much as a few of us have tried we have not been able to find a source in optical or infrared for the x-ray point source indicating that the progenitor star that made the supernova may infact be a black hole rather than a neutron star which is what makes this object so interesting.
This initiative started when the Decadal Survey was released about 2 years ago now. At the moment all the "publicly" available data is spread across multiple depositories, one major one in France and then the NASA Hubble/Chandra/everything else depository and then the individual surveys (2MASS, Sloan, NOAO Deep Wide, etc. ..) are archived but can prove to be a pain to obtain. More than anything whomever does all this archiving must have a bunch of hard drive space. . ..for the NOAO Deep Wide Field we've got something like a terrabytes worth of data and we're still getting more. . ..to heck with travel expenses when you have to pay for new 100 gig hard drives every other month. . . .
Yeah and it's too bad the people on the team have fried some of the coating on their detector. Take that and add an gamma/ x-ray detector and lookin the ecliptic at Sco X-1, the freaking brightest x-ray source in the whole damned sky and you aren't going to detect anything because you're busy frying your detector. The satellite is good- the execution of the science is crap!
Never mind additional months from Jan to July/Aug of this year where they had to write and upload new software because what they had didn't work. This is why satellites like this should not be run by people at Goddard!
First off : you should be able to get info such as pixel sizes from the manufacturer (typical pixel sizes for CCDs are in the in the 10^-12 range for scientific grade CCDs)
In arrays CCDs are fairly good. ..all CCDs have problems with charge transfer efficiency of course but if you're willing to gut your digi cam you'd find out about that. Also you will start to get quantum efficiency problems if it's not a good chip- so your detection of photons as a function of wavelength will be very poor. And then there biggest problem with digi cams are the read noise as CCDs don't do to well with out being cooled.
Software wise I'd recommend you go track down your local astronomer and ask them about IRAF or IDL. IRAF is free from the National Optical Astronomy Observatories and is made to work well with CCD images. The same goes for IDL but it costs arms and legs (say roughly $1000 for a license!). I think the best advice you can get is 1) cantact the manufacturers on the technical info they have and then 2) track down your local observational astronomer. They can tell you about gain, read noise, shot noise and tell you about fun effects like diffraction fringes at redder wavelengths that you can get with CCDs.
Slashdot Mirror
Depends which telescope. It's not unheard of now to have 10 or more GB by the end of a run with multi CCD camera these days.
I take images with boring small cameras so I get about 500 MB worth of data a night.
With MOSAIC on Kitt Peak (a 6 CCD system) the average night worth of data is about 13.5 GB. Too many nights and you need lots of tapes or lots of compression.
There's a bunch of astro people from Arizona who read- I'm just a misplaced Arizona person working for SIRTF at Caltech.
And as to the tapes- I shutter to think what will happen when SIRTF launches- one observation with MIPS pukes out 80 GB of raw and processed data plus masks. Downlinking all that data via the DSN is going to be a cow. Thankfully I'm applying to grad schools next year so I don't have to deal with it that much!
I'm glad people got out of Stromlo- news is that there was a visitor there from Canada who was asleep and had less than 5 minutes to haul out of there.
What I think is the most impressive quote from the Stromlo emails I've seen lately: "The telescopes are all still "hanging" on their mounts, but are not recoverable. The 50" looks like it is parked, but the lower end of the mount is melted and the mirror is a pile of goo on the floor, the Yale lens is on the floor, and the 74" mirror is damaged far beyond repair. " The amount of heat needed to flash melt a 50" diameter piece of glass that was probably about a foot thick is impressive and ungodly at the same time. . .
You know the whole backup thing at the 90 inch only works if you remember to bring tapes up with you (which I forget on a regular basis but you know I'm a closet blonde). I just sftp my data back to multiple computers back at Steward to take care of the problem :0
The KPNO system is very nice- the Save the Bits archive makes multiple tapes of the data that get stored in the 4 meter and down in town and data gets ftp'd down to one of the NOAO Tucson servers as well. So it's on hard drive in multiple places as well as on tape in multiple places as well.
As to Stromlo- somebody brought down all the backup tapes to Canberra on Friday (the day before the fire) so most of the data was saved.
Unfortunately though a lot of us astro people are going to suffer in the near future when DAT drives stop being the best way to store our data. . .hell I have a desk drawer of DAT and DLT tapes as well as CD ROMs with data right now!
What? Hello, Thornton has become what people in Colorado hate- urban sprawl. . . That said. . .yes IKONOS makes pretty pictures but the fact that Lockheed had the technology lets you know they had done it before for someone else- namely the US military. Scary enough that I can get 1 meter resolution images off the internet but the resolution is infinately better in military satellites with adaptive optics. . .
1- I am an astronomer so I wouldn't pay at all, I'd just apply for time through CalTech which is where I work for SIRTF 2- While whomever pays for this will get a spiffy tour of the telescopes will probably wind up in the control room at Waimea which is not on the mountain. Why? Because generally astronomers are out of shape or get loopy at altitude. The way to minimize stupid mistakes is to only let the operators move the telescope and tweak the instruments and keep the astronomers down near sea level. That said I've done a few dumb things at telescopes myself when it was 3 am and I just wanted to go to bed at telescopes at only 7000 ft altitude. . .
Um you guys didn't note at the bottom of their discussion of their journals that publication is not free- instead like other journals they charge you page fees to get your work printed! This is like all other journals where a lot of the grant money goes to publication (Astrophysical Journal charges $150 per page for the print edition and $120 per page for the electronic edition). This is why we should do away with journals and expand arxiv (xxx.lanl.gov)!
Ahh gee read the article- VPL is for the theory end- it's where scientists can model planet formation for both our solar system and others. Part of the purpose of VPL is to be able to model the formation of our own solar system so we can greater understand other solar systems and solar systems with brown dwarfs. TPF- Terrestrial Planet Finder is the telescope that will come after SIRTF and NGST (now know as the James Webb Space Telescope). Also, Vikki is not the "creator" of anything- she is the Principal Investigator for the NASA Astrobiology Institute and she is also on the Science Working Panel for TPF.
As an astronomer who studies Cassiopeia A- I will admit that this picture doesn't really say alot to the public other than "Hey pretty picture" and it is NOT a dying star! The reason it is of interest is because the Chandra Space Telescope first saw evidence of a point source at Cas A's center indicating a remnant of the supernova explosion that hasn't been seen in any other wavelengths. Much as a few of us have tried we have not been able to find a source in optical or infrared for the x-ray point source indicating that the progenitor star that made the supernova may infact be a black hole rather than a neutron star which is what makes this object so interesting.
at http://xxx.lanl.gov/abs/astro-ph/0111538 in various formats. . . . .
This initiative started when the Decadal Survey was released about 2 years ago now. At the moment all the "publicly" available data is spread across multiple depositories, one major one in France and then the NASA Hubble/Chandra/everything else depository and then the individual surveys (2MASS, Sloan, NOAO Deep Wide, etc. . .) are archived but can prove to be a pain to obtain. More than anything whomever does all this archiving must have a bunch of hard drive space. . . .for the NOAO Deep Wide Field we've got something like a terrabytes worth of data and we're still getting more. . . .to heck with travel expenses when you have to pay for new 100 gig hard drives every other month. . . .
Yeah and it's too bad the people on the team have fried some of the coating on their detector. Take that and add an gamma/ x-ray detector and lookin the ecliptic at Sco X-1, the freaking brightest x-ray source in the whole damned sky and you aren't going to detect anything because you're busy frying your detector. The satellite is good- the execution of the science is crap! Never mind additional months from Jan to July/Aug of this year where they had to write and upload new software because what they had didn't work. This is why satellites like this should not be run by people at Goddard!
First off : you should be able to get info such as pixel sizes from the manufacturer (typical pixel sizes for CCDs are in the in the 10^-12 range for scientific grade CCDs) In arrays CCDs are fairly good. . .all CCDs have problems with charge transfer efficiency of course but if you're willing to gut your digi cam you'd find out about that. Also you will start to get quantum efficiency problems if it's not a good chip- so your detection of photons as a function of wavelength will be very poor. And then there biggest problem with digi cams are the read noise as CCDs don't do to well with out being cooled.
Software wise I'd recommend you go track down your local astronomer and ask them about IRAF or IDL. IRAF is free from the National Optical Astronomy Observatories and is made to work well with CCD images. The same goes for IDL but it costs arms and legs (say roughly $1000 for a license!). I think the best advice you can get is 1) cantact the manufacturers on the technical info they have and then 2) track down your local observational astronomer. They can tell you about gain, read noise, shot noise and tell you about fun effects like diffraction fringes at redder wavelengths that you can get with CCDs.