Hi David and Richard,
Thank you for the clarifications
and comments. The application of
occultation results to Hipparchos proper
motion studies and to the
solar radius analysis is remarkable. This is great
work and terrific
professional-amateur collaboration.
David - Where
you mentioned imminent lunar spacecraft missions I
supposed you were
referring to NASA's Lunar Reconnaissance Orbiter.
Are there others that are
relevant? From what I understand about
Clementine, their control network was
significantly different from
ULCN 2005, even up to 10's of km in some places
I think. However USGS
now has a transformed Clementine data set that is
consistent.
Richard - In case you're not familiar with LRO, the laser
altimeter is
expected to produce a global topographic map with 10 cm
vertical
resolution. The maximum horizontal spacing is 30 m with much
closer
spacing at the poles. If the mission is successful, the elevation
data
set might be worth mapping into a lunar limb profile data
set.
There is one additional comment I have on the web site. I was
confused
about the authorship of the Word document. While it is attributed
to
C.B. Watts it appears to be have been written much more recently
(by
Richard?). Thus, I think that the charts should be attributed to
Watts
but the by-line on the Word document should reflect its actual
author.
Best regards,
Tony
Mallama
240-997-1269
Member:
American Geophysical
Union
American Astronomical Society
American Association for the
Advancement of Science
On Wed, Feb 27, 2008 at 10:23 PM, Dunham,
David <David.Dunham@jhuapl.edu> wrote:
>
>
Tony,
> Note that soon my account here
at APL will be closed, and my
> new office e-mail address will be
david.dunham@kinetx.com . You
> asked (see below for my comments):
>
___________________________
>
> Hello Richard and
David,
>
> I found your Watts web site to be very interesting, and
it raised a
> few questions and comments in my mind.
>
> Are
the charts strictly of historical interest, especially given the
>
accuracy of the Clementine data, or are they still valuable for
> research
purposes?
>
> - They are still the most comprehensive charts we have
of the
> lunar profile as seen from locations on the surface of the
Earth,
> so they are still used for analysis of timings of occultations
and solar
> eclipses. The other lunar models, DEM's, etc. don't
represent
> the profile with the Earth-based perspective that we need;
trying
> to convert them to such a form is not trivial. Also, especially
in the
> polar regions (with the exception of the "Cassini" regions that
could
> not be mapped by Watts, the areas immediately away from the
Earth
> from the poles), they are better than Clementine, whose laser
altimeter
> did not reach those areas; with the poor lighting conditions,
there were
> difficulties in defining the models in those areas. Watts had
those
> problems, too, but we've been able to determine corrections to
improve
> the accuracy using grazing occultation
observations.
>
> Have the charts been tied to the Unified Lunar
Control Network of
> 2005? If not, can you estimate the biases between the
charts and the
> ULCN? See http://pubs.usgs.gov/of/2006/1367/
.
>
> - As far as I know, that has not been done, but I'm copying to
others
> to see if they know; as noted above, the difference in
perspective
> makes such comparisons quite difficult. I think the
consensus is
> that it's not worth (our) effort; we'll wait until a much
more detailed
> (especially in the polar regions) network is defined from
the current
> and eminent lunar orbiters before we attempt
this.
>
> Are new grazing occultation timings still useful and, if
so, in what
> way? That is, for lunar mapping, libration studies,
secular
> acceleration ... ?
> They are of use for improving the
Earth-based-perspective (Watts)
> profiles that are also used for analysis
of observations of total and
> annular solar eclipses observed from near
the edges of the paths
> for determining variations in the solar diameter.
They are also
> still powerful observations for discovering and resolving
close double
> stars. Some more is on IOTA's lunar occultation Web
site at
> http://www.lunar-occultations.com/iota/iotandx.htm
. This includes
> a link to Mitsuru Soma's 1999 paper at
> http://ads.nao.ac.jp/cgi-bin-jp/display/pub/vol5/099/0001
that notes
> the observations also might be used to determine errors in
the
> Hipparcos system of stellar proper motions.
>
> There
should also be a mention of the digitized version of the charts
> that are
available at Centre de Données Astronomiques de Strasbourg
> and their
source which is as follows. Morris, L.V. and Martin, R.J.
> 1971 "A
digitised version of C. B. Watts' charts of the marginal zone
> of the
moon" Earth, Moon and Planets Vol 2, pp 463-467. [There are
> also notes
by D. Herald from May 2006 on this data available at
> http://cdsarc.u-strasbg.fr/ftp/cats/6/122/doc.txt.]
>
>
- Yes, I agree; I've updated the site to describe and link to this.
>
David
>
> I am interested in your comments and I hope that my
feedback is useful.
>
> Best regards,
> Tony
Mallama
>
> 240-997-1269
>
> Member:
> American
Geophysical Union
> American Astronomical Society
> American
Association for the Advancement of Science
> Then I sent my response as
follows:
>
> Hi Tony: I can answer some of your comments, but
I would have to look into
> some others.
>
> ----- Original
Message -----
> From: "Anthony Mallama"
<anthony.mallama@gmail.com>
> To: <astromaster@sunflower.com>;
<dunham@yahoo.com>
> Sent: Wednesday, February 27, 2008 9:35
AM
> Subject: Lunar Marginal Zones
>
>
> > Hello
Richard and David,
> >
> > I found your Watts web site to be
very interesting, and it raised a
> > few questions and comments in my
mind.
>
> Thanks for the interest. I started the work in the
early 1990s and had the
> latest revision in the early
2000s.
>
> > Are the charts strictly of historical interest,
especially given the
> > accuracy of the Clementine data, or are they
still valuable for
> > research purposes?
>
> The P&D
Charts were set up as a graphical representation of where one would
> be
experiencing an astronomical event related to the Moon. However,
the
> 1800 Watts' Charts and their computerized children are
astronomically
> significant in providing the most accurate predictions of
astronomical
> events relating to the Moon in profile as observed from
Earth. The
> Clementine Data was too limited (more limited than
expected as I have heard)
> to replace the Computerized Watts'
Charts. However, I understand from David
> Dunham that planned
missions may accomplish this goal at some later date.
> Until such time
then the Computerized Watts' Charts seem to be the best game
> in
town.
>
> > Have the charts been tied to the Unified Lunar
Control Network of
> > 2005? If not, can you estimate the biases
between the charts and the
> > ULCN? See http://pubs.usgs.gov/of/2006/1367/
.
> >
> > Are new grazing occultation timings still useful
and, if so, in what
> > way? That is, for lunar mapping, libration
studies, secular
> > acceleration ... ?
>
> I am unsure on
this question. Perhaps David can shed some light on this.
> Also,
perhaps you could be helpful toward this goal.
>
> > There should
also be a mention of the digitized version of the charts
> > that are
available at Centre de Données Astronomiques de Strasbourg
> > and
their source which is as follows. Morris, L.V. and Martin, R.J.
> >
1971 "A digitised version of C. B. Watts' charts of the marginal zone
>
> of the moon" Earth, Moon and Planets Vol 2, pp 463-467. [There are
>
> also notes by D. Herald from May 2006 on this data available at
>
> http://cdsarc.u-strasbg.fr/ftp/cats/6/122/doc.txt.]
>
>
I am aware of the above sources, and many others, and they are planned
for
> the next update to the Watts Doc on the web page.
>
>
> I am interested in your comments and I hope that my feedback is
useful.
>
> Your feedback is exactly what we need. The idea is
to make something that
> is both historically and scientifically useful to
as many people as
> possible. We can thank David Dunham for his many
decades of work making
> this a field in which it is worth being a
contributor. Thank You!
> Richard P. Wilds
> Lawrence,
Kansas
> (785)845-7304
>
> > Best regards,
> >
Tony Mallama
> >
> > 240-997-1269
> >
> >
Member:
> > American Geophysical Union
> > American
Astronomical Society
> > American Association for the Advancement of
Science
> >
>
> ----- Original Message -----
> From:
Dunham, David
> To: Richard P. Wilds
> Sent: Monday, February 25,
2008 8:38 PM
> Subject: RE: Lunar South Pole
>
>
Richard,
>
> Curious that
as I was preparing a Web page from your material, this
> message
arrived. You can see what I did at http://iota.jhuapl.edu/watts.htm
>
- let me know of any changes you want (in fact, I attach the watts.htm
file
> so you might modify it yourself). I won't have time to work
on this myself
> for awhile, but if you modify it, I can review what you
write and post
> updated versions. I notice that some of the links that
you give in the Word
> document no longer work; you might check them out
and do Google searches to
> try to find current URL's for the material in
question.
>
> David
> ________________________________
>
From: Richard P. Wilds [mailto:astromaster@sunflower.com]
> Sent: Monday,
February 25, 2008 8:42 PM
> To: Dunham, David
> Subject: Re: Lunar
South Pole
>
>
> Greetings David: I would be glad to
work on a rewrite of the Watts paper.
> I could do it or we could work on
a co-author work together. We would need
> to rework the web pages
you gave me a few years back as they are not working
> at this
point. Also, we would need to rework some of the historical
>
listings in light of Dave Herald's material of other past grazes
observed
> from earlier centuries. Please, let me know your
ideas. Thank You!
> Richard
>
> P.S. Take a look
at the Moonlight Kansas PR and its relationship to the
> Watts P&D
Chart. Then take a look at the Whitaker and Hill Charts. I
found
> it quite amazing that I could follow the graze on both the PR and
the
> drawings:
>
> the star, Maia, came in over the mountain
M4
> the star had a D and R into M5 - both M4 and M5 were bright on
the
> terminator and the M5 events were timed due to its blue
color
> the rest of the graze was on the bright side, but in the fainter
light of
> the Cassini Region made events easy to see
> the star
crossed through a deep dark valley with only one of the team
> getting
timings along the bottom
> the rest of us followed the star along the
raised bright hills beyond the
> south pole that ended with the star
having events in M6
> then the Moon pulled away from the star and we
turned back to doing other
> Pleiad totals
>
> This area is
also displayed nicely in Dave Herald's Occult 4's Watts
> subroutine as
long as you input the aapproapriate librations and go to the
>
approapriate Watts Angles.
>
> All of this allows quite a special
rebuilding of a wonderful past
> observation done before the help of
today's video gear.
> ----- Original Message -----
> From: Dunham,
David
> To: Richard P. Wilds
> Sent: Monday, February 25, 2008 5:23
PM
> Subject: RE: Lunar South Pole
>
>
Richard,
> Thanks for all of
these. David
> ________________________________
> From:
Richard P. Wilds [mailto:astromaster@sunflower.com]
> Sent: Monday,
February 25, 2008 6:04 PM
> To: Dunham, David
> Cc: David
Dunham
> Subject: RE: Lunar South Pole
>
>
>
Richard,
>
> Thanks for charts
1-8, received fine so far. When sending the rest of
> the charts,
could you copy to my work address, david.dunham@jhuapl.edu (the
> Cc:
address of this message) since I need them there for posting on my Web
>
site. Thanks,
>
> David
>
> At 10:16 PM 2/24/2008,
you wrote:
> Hi David: I will start sending a few of the charts at a
time so as not to
> overload your inbox. Thank You!
Richard
> ----- Original Message -----
> From: David Dunham
>
To: Richard P. Wilds
> Sent: Sunday, February 24, 2008 6:48 PM
>
Subject: RE: Lunar South Pole
>
>
Richard,
>
> Thanks for these; I've
forwarded them to my colleagues at APL who are
> using lunar polar data to
study landing missions in that area. This reminds
> me that
something needs to be done about your watts.doc write-up; for now,
> I'll
post it on my Web site, if that's all right with you. Do you have
>
scanned images of the P,D charts with the features labelled that you
could
> send to go along with it? The watts.doc file doesn't include
those.
>
> David
>
> At 05:05 PM 2/24/2008, you
wrote:
> Hi David: I sent this to Derek in responce to his notice
about this
> Wednesday's Radar based view of the Lunar South Pole. I
was not sure if you
> had ever seen these drawings. I find them to
be quite accurate in terms of
> preparing for and reviewing Cassini
Grazes. Thank You!
Richard
>
>
>
>
--