PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
October 2014
917
This is an open
invitation to write a
Letter to the Editor
What do you
want to say in
250 words or
fewer? You pick
the topic, but
keep it on point
Let me
start by
complimenting
the
PE&RS
editors, namely Russ
Congalton, Mike Renslow, and Jie
Shan. Our impact factor continues
to climb and is now over 2.0.
The editors put great effort into
offering authors quality feedback
and support, so good job. Let me
also compliment the editorial and
the
PE&RS
production staff and
columnists, namely Rae Kelley,
Matt Austin, Jeannie Congalton,
Jim Peters, Cliff Mugnier, and
Qassim Absullah. In addition to
the regular columns like Grids and
Datums and Mapping Matters,
I have been excited to see the
new columns, such as Member
Interviews, and Behind the Scenes.
I like having both peer-reviewed
technical papers and increased
general interest content together in
the same journal—more for all.
Now let me ask a question. What
do you think of the notion of ASPRS
Special Interest Groups (SIGs)?
Right now, we have technical
divisions, technical committees,
committees of the bylaws, councils,
regions, task forces, and working
groups. Do we have too much
structure encoded into the bylaws
that makes it difficult for us to be
agile? What do members think is
the minimal structure that would
be desirable for ASPRS to function
as a society?
By the way, this letter to the
editor is exactly 250 words, so as
you can see, writers need to write
on point.
INDUSTRY
INSIGHT
Letter to the Editor—Grids & Datums
Dear Professor Mugnier,
Often times I am working with historic map sources and in attempting to research
more about them I stumble across the
Photogrammetric Engineering and Remote
Sensing
Journal online, which has proven quite resourceful a number of times. I am
contacting you after reading your May 2008 contribution to the journal -- Grids &
Datums: Kingdom of Cambodia. I was hoping to get your opinion/recommendation on
the correct datum for a 1907-08 map series of French Indochina, at 1:200,000 scale.
I am familiar with the use of Grads on these early 1900s French maps, however this
particular series does not use them, and shows graticule at 20 minute intervals. There
is also a note beneath the scale bar --
Developpement sinusoidal suivant le meridien
101° 40’
which I have assumed refers to the map being in Sinusoidal projection with
101° 40’ central meridian. Based on grid labels I am also confident that this map uses
Paris as prime meridian.
Do you have any recommendations on a datum the French may have used in this
region at this time? I appreciate your time, and your contribution to
PE&RS
journal!
Best Regards,
K. Danaher, International Mapping
Dear Mr. Danaher,
Since you think they likely used Paris as their prime meridian, my first guess would
be Belvedere Datum in Vietnam. You can still find the origin point in Hanoi with
Google Earth at Mirador Tower at φ
o
= 21º 01′ 57.27″N, λ =105º 50′ 23.33″E (WGS84
Datum/Ersatz Google datum). Original ellipsoid was likely Clarke 1880 (IGN).
Note that at 1:200,000 scale it’s pretty much impossible to identify datum and/or
ellipsoid used. It DOES impress the clientele, though.
Best regards,
Clifford J. Mugnier, C.P., C.M.S.
Louisiana State University
Attention Students
The ASPRS Scholarships application
deadline for the 2015 awards year is
October 31, 2014.
For details, go to:
education
