Photography That’s Cosmic: Harvard’s DASCH Project
Dr. George Champine
From Daguerre to Digitizing the Sky, George Champine brings astrophotography to earth for the January 6 meeting
Harvard University’s DASCH project will eventually do just what its name says: provide Digital Access to a Sky Century. Harvard has the resources, a century’s worth of telescope images, some 500,000 of them collected from observatories around the world — glass
plates, daguerreotypes dating from 1849, wet collodion plate images primarily from the 1870s, and early stereoscopic and spectral plates.
But digitizing the collection needed technology. To complete the project on a reasonable schedule and budget, the DASCH project had to develop the world’s fastest (by a factor of 50x) and most accurate (by 10x) digitizer.
PHSNE member George Champine is a volunteer working on the DASCH project (he’s photographed 80,000 pages of notes on the plates). As a physicist and computer scientist now retired from a career with companies including DEC, Exxon, and Sperry Univac, George will be the perfect guide for a tour of the history of astrophotography and its transition from analog to digital for PHSNE’s January 6 meeting at Waltham High School. (He’s also preparing an article for The Journal on DASCH.) For more on the DASCH project, read The New York Times article at http://tdc-www.harvard.edu/plates/publications/GJ1NYT.pdf.
-From snap shots, January 2008.
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Presentation Slides
George's presentation (no audio) is available below. Clicking on each slide will take you to the next slide.
Presentation by George Champine.
The presentation (no audio) is also available as a pdf file. The smaller file is DASCH_Project_by_George_Champine-small.pdf (2.8M Bytes. Contains all the text and images, but the resolution has been reduced in the images to reduce the file size for slower internet connections. Fine for normal monitor sizes.). The larger file is DASCH_Project_by_George_Champine.pdf (14M Bytes).
For information on reading pdf files on Windows and Mac computers see PDF Files in Using This Site section.
Video of the DASCH Digitizer in Action
A movie of the digitizer in action was presented at the meeting and is available (2 minutes, 8 seconds of video) on the internet at the DASCH site. Click here to see the video as a Windows wmv video. The video will be more informative if you have read the presentation first as there is no explanatory audio on the video. In the video you see two star plates being loaded and the digitizer scanning the plates. You see the flash of the digitizer LED illumination system, but not on every step of the motion table as the plates are scanned. This is due to the "strobe" effect of the video camera frame rate and the timing of the digitizer illumination flashes.
Show-and-Tell
The show-and-tell event was not recorded at this meeting.
More Information
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Plate Stacks
| A web site with lots of information about the Harvard College Observatory Astronomical Plate Stacks including links to other articles for both a general and professional audience.
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DASH
| DASCH home page.
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Movie
| Short movie of DASH digitizer in action.
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Digitizer Description
| "An ultrahigh-speed digitizer for the Harvard College Observatory
astronomical plates" a technical paper by the design team about the digitizer. Posted at Cornell University's arXiv server.
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