894
December 2015
PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
ever write about two neighboring countries two months in
a row. That pretty much worked, but some of the randomly-
chosen countries appeared to have nothing published at all
concerning their geodetic history. Fortunately, I was able
to frequently obtain the assistance of Mr. John W. Hager, a
geodesist retired from what is now the National Geospatial-
Intelligence Agency. If nobody in the world had the
information, John had it in his unclassified personal notes
and he has graciously helped me with my columns over the
years. Another friend that helped me innumerable times was
Mr. Malcolm A. B. Jones of Perth, Australia; a close friend of
several decades that shares that same interest in coordinate
systems (and humorous stories) with me. From time-to-time,
the late Jim Cain provided wonderful insights to various
minutiae geodetic
.
The series is done. What else is there to write about? I
have decided to get up-to-date, and write about current
developments primarily in physical geodesy – gravity. The
U.S. National Geodetic Survey has commenced the aerial
survey of the Earth’s gravity field of the United States, its
territories and possessions in order to develop a more accurate
and precise geoid with “GRAV-D.” Much photogrammetric
mapping is nowperformedwithGPS-controlled aerial imagery
and lidar, and one limiting factor is the geoid. The NGS is
doing aerial gravity surveys, and a number of people are also
doing terrestrial gravity surveys; all with the same objective
of improving the geoid. A book may come from the Grids
& Datums columns with some updates, but the continuing
columns will be likely less frequent but concentrated more
on current developments, perhaps with some historical
background. Hopefully the readers of
PE&RS
will find this
of interest.
The contents of this column reflect the views of the author, who is
responsible for the facts and accuracy of the data presented herein.
The contents do not necessarily reflect the official views or policies of
the American Society for Photogrammetry and Remote Sensing and/
or the Louisiana State University Center for GeoInformatics (C
4
G).
Attention those seeking ASPRS Certification:
ASPRS Online Seminars are a great way to
gain Professional Development Hours!
/
GISD-Division/
Online-Seminars.html
January 29
th
Fusion of Geodesy and GIS at NOAA’s
National Geodetic Survey
Brian Shaw, NPS
February 26
th
Beyond NDVI … 2016
Jack Paris
March 25
th
A Geospatial Approach to Mapping
Environmental Sound Levels Across the
United States
Dan Mennitt, NPS
Kurt Fristrup, NPS
April 29
th
Designing National Park Service Visitor
Maps
Tom Patterson, NPS
May 27
th
CyberGIS: Foundations and Principles
Eric Shook, Kent University
July 22
th
Getting More From Remote Sensing
Data Using OGC Standards
George Percivall, OGC
August 5
th
Aqueduct Global Flood Analyzer – A
Web Tool To Estimate Global Flood Risks
For Current and Future Scenarios
Tianyi Luo, WRI
New!
GeoBytes!
ASPRS GIS D
ivision
—
F
ree
O
nline
S
eminars
The ASPRS GIS Division, in cooperation with
CaGIS and GLIS, is sponsoring free online live
seminars throughout the year.
A special offer to
ASPRS members from
CRC Press!
40% Discount
to all ASPRS members!
See page 885 for more details and the promo code.
