posted
"A full spherical sky search is 41,000 square degrees. A wide angle lens will cover about 100 square degrees (a typical SLR personal camera is about 1 square degree); you'll want overlap, so call it 480 exposures for a full sky search, with each exposure taking about 350 megapixels.
Estimated exposure time is about 30 seconds per 100 square degrees of sky looking for a magnitude 12 object (which is roughly what the drive I spec'd out earlier would be). So, 480 / 2 is 240 minutes, or about 4 HOURS for a complete sky survey. This will require signal processing of about 150 gigapizels per two hours, and take a terabyte of storage per sweep.
That sounds like a lot, but...
Assuming 1280x1024 resolution, playing an MMO at 60 frames per second...78,643,200 = 78 megapixels per second. Multiply by 14400 seconds for 4 hours, and you're in the realm of 1 terapixel per sky sweep Now, digital image comparison is in some ways harder, some ways easier than a 3-D gaming environment. We'll say it's about 8x as difficult - that means playing World of Warcraft on a gaming system for four hours is about comparable to 75 gigapixels of full sky search. So not quite current hardware, but probably a computer generation (2 years) away. Making it radiation hardened to work in space, and built to government procurement specs, maybe 8-10 years away.
I can buy terabyte hard drive arrays now.
I can reduce scan time by adding more sensors, but my choke point becomes data processing. On the other hand, it's not unreasonable to assume that the data processing equipment will get significantly better at about the same rate that gaming PCs get significantly better.
Now, this system has limits - it'll have trouble picking up a target within about 2 degrees of the sun without an occlusion filter, and even with one, it'll take extra time for those exposures.
It won't positively identify a target - it'll just give brightness and temperature and the fact that it's something radiating like a star that moves relative to the background.
On the other hand, at the thrusts given above, it'll take somewhere around 2 days of thrust to generate the delta v to move from Earth to Mars, and the ship will be in transit for about 1-4 months depending on planetary positions."
IP: Logged |
posted
I'll disagree with the blanket dislike of opening in dreams. I think that in some situations a dream situation can set the tone of the story. A dream can highlight what is absent in real life.
However, they shouldn't be too long (that is, two pages is pushing it) and they should be really crucial and the division between the dream and reality should be as clear to the reader as it is to the character having the dream.
(Unless of course, the whole point is the confusion, and then we're getting into literary masterpiece territory.)
Posts: 8473 | Registered: Apr 2003
| IP: Logged |
Blayne Bradley
unregistered
posted
Its about two to three pages and fairly briskly paced.
IP: Logged |
Blayne Bradley
unregistered
posted
"Old soldiers don't die, they just fade away."
Anyone else while recognizing a sort of beauty to this statement also very much would like to see a story where this isn't the case? Where the lesson instead of Old Soldiers going away or stepping to the side is that they should *always* be near and at ready in case they and they're skills and experiences are still needed and appreciated?
IP: Logged |
Printer-friendly view of this topic
![[Razz]](tongue.gif)
territory.)
