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Re: Interesting reading
Chris and all,
We shall see. I am having lunch with him April 24 when he gives a talk at
Fermilab. I think I posted that here. If anyone here wants to get to the
talk, I will check on what has to be done with security. It has been a
pain since 911.
I wrote him about what we were doing, but he did not write back. I think
we are competition.
As for camera lenses. I tried a few. They do not have very flat
fields. The one I tried drooped about 50% at the edges. Elliot's design
looks like a few percent. I don't know about the particular Leica lens,
but ROTSE used the best camera lenses that they could find, I think from
Canon, and they have a big variation across the field. They paid a similar
amount. The field was much less flat (5x?) then we achieve with the Elliot
Burke design. The field flatness goes as some high power of the bandwidth
when you try to optimize it. So Elliot and I made use of this when the
lenses were designed. The history is that I discovered this from talking
to lens designers. Then I just kept hunting until I found someone willing
to have a go at it. It was an awful experience, getting the lenses right,
but now I am glad we did it since we now have a bragging point. Not sure
it really matters for the result. I should have worried more about lens
baffling.
I think the life of tass depends on using filters. I would not encourage
the competition to use filters. ;^). The economics of these surveys is
such that they don't work at big observatories. It is too costly to pay
astronomers to sit at the observatory many months of the year. Sure! They
will be run remotely for months without requiring attention.
The more I look at Michael's software the more impressed I am with it. It
is well documented. Once we run a lot of data through it and have
problems, it will be easy to make changes. We shall see if we can say the
same about Dr. Charbeneau. I will try to get his software, but we shall
see what he makes available.
He seems to be getting a lot of publicity. You can't both do work and give
talks everywhere. My goal is to let the results do the talking. We are
pretty close.
Below is the note I wrote him.
Tom Droege
Hello,
I am looking forward to meeting you when you come to Fermilab in April. I
have started an amateur group called The Amateur Sky Survey (tass). I am
building a number of 400mm fl f/4 dual camera systems with 2k CCDs to
perform an all sky survey. At least one of our group intends to use a
system for a planet search. While we cannot do photometry at your level,
we hope to provide candidates for projects such as yours. See
http://www.tass-survey.org for more information about tass. TN-81 is one
example of the data analysis work. I did not have much luck getting
through your web site to an actual paper. Possibly you can direct me.
Tom Droege
At 09:35 AM 3/8/02 -0800, you wrote:
>I like the part where it says
>
> "An amateur astronomer could do this, except maybe for
> the debugging of the software, which requires several
> people working 10 hours a day,"
>
>I'm sure most of us would agree.
>
>The project sounds almost identical to the Mark IV except they
>are using a shorter focal length lens but a much higher quality
>Leica makes a 280mm f/4.0 lens. They don't make a 300 so I assume
>someone rounded up. Lenses don't get much better quality then
>Leica. It sells for $4600. Being such a sharp lens their stars
>are even more under sampled then TASS'. Maybe a one pixel PSF?
>They are likely using a very sturdy computer controlled mount too.
>
>The Dollar figure on the CCD says they may even be using the same
>CCD as the Mark IV, just the #1 grade.
>
>They don't talk about filters but then this is a press release for
>the general public.
>
>I would be very much be interested in finding out about their
>software. Whatever they use would be directly applicable to TASS
>as it is clear TASS and this system are a lot a like.
>
>
>
>=====
>Chris Albertson
> Home: 310-376-1029 chrisalbertson90278@yahoo.com
> Cell: 310-990-7550
> Office: 310-336-5189 Christopher.J.Albertson@aero.org
>
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