From: xxxx
To: John Lenard
Subject: Re: ISS photo
Date: Wed, 17 Jan 2007 17:57:34 +0000 (GMT)
********************************************************
xxxx FInstP ScD
Professor of Experimental Philosophy
Institute of Astronomy
Cambridge University PA: Suzanne Howard
Madingley Road
Cambridge CB3 0HA UK
*******************************************************
Hi John,
many thanks for sending your remarkable images: you are clearly
an exceptionally talented astro-photographer.
there are of course very many communication, spy and
earth-observation satellites in orbit. The best information
source I know to identify such things is a distinguished
astrophysicist, who used to work here in Cambridge and now works
at Harvard, Jonathan McDowell.
his (relevant) web page is
http://www.planet4589.org/space/jsr/jsr.html
and I've taken the liberty of cc'ing him on this reply.
best regards, and good luck in the hunt.
xxxx
On Wed, 17 Jan 2007, John Lenard wrote:
Dear xxxx
I think Jonathan McDowell is the perfect person, along with you,
to solve the films
of mine. I would love to show you the real objects on the moon.
when jpl/nasa saw my moon video, they did not know what I had
gotten on my tape.
look at file moon walk jpg file
thank you. I am looking forward to speaking to Jonathan McDowell
regards,
John
From xxxx
Sent: Thu 1/18/07 3:37 AM
To: John Lenard
********************************************************
xxxx FInstP ScD
Professor of Experimental Philosophy
Institute of Astronomy
Cambridge University
Madingley Road
Cambridge CB3 0HA UK
*******************************************************
Hello again,
And again my congratulations on your superb astrophotography.
You are clearly getting some images at almost the diffraction
limit of your telescope. In the very sharpest images there are
hints of diffraction rings visible on the edges of the
satellites. That is of course the absolute limit of optical
performance, and is only rarely attained.
Interestingly, the process you have, of using a high-quality
imaging system, with fast read-out, and then selecting the rare
`perfect' images is something which has been developed and
applied somewhat by one of my colleagues here. You might like to
look at our local web page presenting some of this:
http://www.ast.cam.ac.uk/~optics/Lucky_Web_Site/
You might also be interested in a journal produced by the MIT
Lincoln Laboratory - which is the group which has built some of
the things you are seeing. Much of what they do is what used to
be the Star wars project, which no doubt involves some of your
objects. They don't talk about the military satellites, of
course, but there are many discussions of earth surveillance,
and related issues.
It is distributed only to academic
organizations, so you may need to get your local library to
borrow it, but you may be able to get this (for free) from:
Subscription Coordinator
Room L-054
Lincoln Laboratory
MIT
244 Wood Street
Lexington
MA 0240-9185
USA
best regards
xxxx
From xxxx
Sent: Thu 1/21/07
To: John Lenard
********************************************************
xxxx FInstP ScD
Professor of Experimental Philosophy
Institute of Astronomy
Cambridge University
Madingley Road
Cambridge CB3 0HA UK
*******************************************************
Hi John,
my work address is perfectly safe, thanks.
I wouldn't worry too much about Nasa restricting you or your
information. They are a civilian agency, and astronomers work
with them all the time. Many of my colleagues are indeed nasa
staff.
There is of course nothing like posting stuff on the internet if
you do feel restricted.
But perhaps more useful might be for you to get the coordinate
information to Jonathan so he can identify some of these for
you.
ciao
xxxx
From: xxxx
Sent: Sat 2/10/07 2:37 AM
To: john lenard
Hi John,
Thank you for the images: once again they show that you are an
excellent photographer.
There are of course many satellites in orbit, only a few of
which are anything to do with JPL, but these are readily seen by
astro-photographers like yourself all over the world.
You should just enjoy the excellence of your images, and make
them available as widely as is possible, through the public
web-sites, magazines, etc, so you can get the credit you deserve
for your skills.
best regards
xxxx
John Lenard wrote:
Dear Jerry
One more important point...
what should a five and an 8 inch scope see?
From: xxxx
Sent: Fri 4/06/07 8:34 AM
To: John Lenard
********************************************************
xxxx FInstP ScD
Professor of Experimental Philosophy
Institute of Astronomy
Cambridge University
Madingley Road
Cambridge CB3 0HA UK
*******************************************************
Hi John,
A telescope does two things: it collects more light than an eye,
so allows one to see fainter (sensitivity), and it increases the
amount of detail (resolution) that one can see.
Sensitivity is simple: it gets better the bigger you are, so you
will always see fainter objects with a bigger telescope: that is
why astronomers like to build big things,
Resolution is more complicated: the finest detail you will see
with a telescope depends mostly on the local atmosphere where
you are. This 'seeing' is caused by turbulence in the air,
usually at low levels. There is a typical size to these
air-parcels, which is a few inches. At a site with very good
seeing the parcels are up to about 10-12 inches, more typically
they are 5-6 inches at a good site, 1-3 inches are a poor site,
or in bad weather. The air-patches, bubbles, are blown by the
wind, so keep changing as seen by one person/telescope, which is
why some frames have a lot more detail than do others. most of
Southern California - in fact all west-facing ocean coasts - are
very good sites, with Mt Wilson and Palomar being famous
examples.
The effect of this turbulence is that telescopes only see more
and more detail until the telescope is larger than the air
bubbles. When several bubbles are seen by the telescope at the
same time the image no longer improves. When it is windy the
bubbles move past quickly, so that the image is changing a lot,
and seems fuzzy. That means that larger telescopes do not see
more detail. In fact, a good back-yard telescope, well-adjusted,
like yours, see just as much detail as a very large professional
telescope, like the Palomar 200-inch. Palomar see fainter of
course, but no `better'.
You will get the best possible image quality with a telescope
about the same size as the bubbles, with a magnification which
is just large enough so that exactly one air bubble is between
the telescope aperture and the target image, and with an
integration (frame-rate) time such that the bubble doesn't move
by more than one-half its size during one film frame.
Your technique of 'lucky imaging' seems to have identified
exactly the correct combination of telescope size, magnification
and frame rate to match your local atmosphere and wind.
You can do a bit better by having a larger telescope - maybe
twice as big - and using a shorter frame rate, but only when the
conditions are very stable, so less often.
Of course, by far the biggest limitation most systems have is
poor focus and wobble - poor mounts. Most systems don't work
anywhere near their potential simply because they are not setup
properly.
You can do better by trying to 'correct' the image for its
distortions: that is called adaptive optics, and there are some
quite good systems available. Hand-held video cameras already
have them built-in, to correct for focus and hand-shake.
So, bigger doesn't always mean better. It depends what you want
- to see faint, or to see detail. You can't have both, unless
you get above all the air - which is why we build our telescopes
on the top of very high mountains, or put them in space. That,
however, is expensive.
regards
xxxx
From: "xxxx II" jpl.nasa.gov
To: "John Lenard"
Subject: other good film
Date: Sat, 10 Mar 2007
Hi John.
Wow! I'm impressed. It's either enormously huge (so you can see
it as being larger than the bright stars in Orion) or closer
than space.
And the movie is the best ever.
How do you know when to set up your camera? Or where to point
it? I hope you don't mind all my questions.
Have a good weekend.
--xxxx
From: John Lenard
To: xxxx.
Subject: other good film
Date: Sun, 11 Mar 2007 09:42:09 -0800
Dear xxxx
This film is very good. I hope you like it.
yours,
John
From: xxxx
To: John Lenard
Subject: other good film
Date: Wed, 21 Mar 2007 10:12:02 -0700
Hi.
Yes. It appears to have symmetrical rectangular appendages,
which are probably solar panels.
It also appears to be rotating on its X-axis a little -- Thanks
for remembering to show me your stuff.
j--xxxx
