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RE: dB timings - RE: A Data Reduction Proposal
Hey Arne,
No problem. The 250,000 stars came from a complete reduction of data from
night 2157 using DAOPHOT and my own software. There are 88 images of the
single field TOM tracked, 44 V and 44 I, which were reduced and imported. I
like this set as it's a manageable size and tracks a single field. So, for
200 images, we'd hit 500K stars. I band hit about 5K per image, V band
about 3.5K per image. Could be my usage of DAOPHOT. One of these days,
I'll pick your brain on that.
As with what I told Chris, I'll start (this weekend?) throwing more data at
the dB, probably just re-importing the same data sets with some random
perturbations and see what happens when the dB increases size. I believe my
computer is on the slow end of useful, as it's the cheapest AMD K6-2 500Mhz
system I could build four years ago. The 640Mb of memory helps things along
quite nicely, especially with the dB.
Cheers,
Rob
> -----Original Message-----
> From: aah@nofs.navy.mil [mailto:aah@nofs.navy.mil]
> Sent: Tuesday, February 05, 2002 1:29 PM
> To: tass@listserv.wwa.com
> Subject: Re: dB timings - RE: A Data Reduction Proposal
>
>
> Rob,
> For your timings, and I apologize ahead of time for
> not following the entire discussion, was the import and merging
> of 200K "stars" basically a single-filter detection of 200K
> separate stars that you then add to the database? The
> reason I ask is that the baseline that was discussed many
> moons ago for a single night was the following:
> [200 2kx2k images (100 each V and I), each with 5K stars]
> that is 1M entries per night to add to the database if I've done my
> math right. If your estimate of 7hrs for 200K stars is
> right, then 35 hours would be required to import/merge one night
> of data from one site with your computer. This doesn't
> depend on the size
> of the database? My estimate is about 60M real stars will be present
> in the Mark IV database, along with an approximately equal number of
> nonreal objects.
> Arne
>