There was so much more content in the WWDC presentation, I wished they had filmed lunch sessions at the time:
- It was not only moon orbiter pictures but also stuff from the apollo missions
- The analog pictures were actually transmitted over radio with an analog process (converting black and white in frequencies)
- This signal was then digitized and used to recreate images on the ground
- What they use (at least what they showed 4 yers ago) is the raw sound files that were recorded. Of course this is much better than the recreated on the ground images because you are one step closer to the source.
- They first had to find a way to read those files on tapes. They actually called this presentation "data archeology" because of this. Had to find tape readers, get them back to work, etc.
- Using DSP processing they were able to significantly improve the quality of the reconstruction process, dealing with mechanical problems on the space side (like the film were moving on a roll which speed was not perfectly constant)
- One of the most interesting result was an image reconstructed in 2000s compared to the original image. Turned out to be one of the first picture of earth poles (and ice cap). Extremely useful today.
For more info:
Found the slides from the wwdc presentation!
2:36 Dennis Wingo "I really want this material to be to be conserved, part of scientific validity is to be able to go back to the original sources."
Nice catch. I am a 'vicarious lunatic' and look forward to the publication of this material.
Please, anyone with budgetary power, pause for thought about the preservation of raw data for the future
The preservation efforts are really vital. I was amazed at how much data is "trapped" in media that is slowly decaying over time at NASA. Definitely worth saving.
Love this kind of reporting, and the characters.