PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
January 2018
13
continuous operation reference stations has been unfolded
step by step. The satellite navigation positioning continuous
operation reference station network with centimeter-level
real-time positioning precision has been completed or is being
built in 24 provinces (autonomous regions, municipalities),
and over 1,200 continuous operation reference stations have
been newly built. The work related to quasi-geoid refinement
has been carried out in 26 provinces (autonomous regions,
municipalities), of which 25 have completed the work and
23 have reached the centimeter-level precision. Based on
the quasi-geoid refinement, GPS C network construction
and Class-C leveling survey have been carried out in most
provinces, municipalities and autonomous regions.
In June, 2012, the project of infrastructure construction of
the national modern datum reference system for surveying
and mapping (phase I), which is a major special surveying &
mapping project of China during the 12th “Five-year Plan”
period, was officially kicked off. The project is expected to,
in the next 4 years, build 150 reference stations, reform 60
GNSS positioning continuous operation reference stations
and make direct use of 150 reference stations, thus forming
a national satellite positioning continuous operation datum
network consisting of 360 reference stations; build 2,500
satellite geodetic control points, make direct use of 2000
points, thus forming a 4500-point national satellite geodetic
control network, which constitutes the new-generation
geodetic datum framework together with the national
satellite positioning continuous operation datum network;
build and rebuild 27,400 height control points, lay 110
leveling bedrock points, deploy the national Class-A leveling
network with a length of 122 thousand kilometers and form
the national modern vertical datum framework; deploy 50
national gravimetric datum points, improve the national
gravity datum infrastructure; build 1 national surveying &
mapping datum data center and form the national modern
surveying & mapping datum management service system.
Through the implementation of infrastructure construction
of the national modern datum reference system for surveying
and mapping, China plans to complete a high-precision,
geocentric, dynamic, practical and uniform national datum
reference system for surveying and mapping in 2015.
At the end of 2012, Beidou (COMPASS) navigation satellite
system covered the most areas in the Asia-Pacific region and
was officially put in commercial operation. And construction
and maintenance of the modern datum reference system
for surveying and mapping that is based on GNSS (GPS,
GLONASS, GALILEO and COMPASS) have started in some
areas in China
.” (Approved by: National Administration
of Surveying, Mapping and Geoinformation of China 28
Lianhuachi West Road, Haidian District, Beijing, 100830,
China, 2013-12-20)
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).
This column was previously published in
PE&RS
.
ther development of the archive not only of US imagery but
worldwide. However, undoubtedly the most significant high-
light of this time period was the decision to provide Landsat
imagery in the entire archive free of charge to anyone. This
development has opened up not only the academic/research
components of Landsat imagery but also has provided for
countless commercial applications.
Chapter 6, the final chapter, is entitled “Landsat: Dedicat-
ed to Continuous Earth Observation” and presents a sum-
mary of the overarching themes from the book as well as the
lessons that have been learned. This chapter is followed by a
short epilogue that contains a little more information about
Landsat 8 and some final thoughts. There are then three
appendices: the first presenting state of the archive maps for
all missions, the second presenting information about con-
current Landsat operations, and the third containing miscel-
laneous information about many who worked on Landsat in-
cluding the various Landsat Science Team members through
the years. These first two appendices present the USGS ar-
chive as of 2008. Fortunately, since that time the USGS has
worked hard to almost double the archive by retrieving much
of the international imagery that is available. The book con-
cludes with a very extensive bibliography and then an index,
both making the information in the book easy to access.
In reading and reviewing this book, I am reminded of all
the effort, commitment, and energy that has gone into pro-
ducing a 45-year continuous archive of amazing imagery of
our home planet. It is truly a phenomenal accomplishment.
To have all this information, including lots of inside stories
that could easily be lost to future generations, all in one place
is a great blessing to our remote sensing community and be-
yond. The Landsat legacy will continue to live on and is more
secure than it has ever been. However, this book provides
all of us with a great history of where we have been and the
struggle to get to where we are today. I guarantee that you
will want to read this book to learn about this history and
then you will keep it to refer to it often as we continue to grow
the Landsat legacy.
BOOK
REVIEW
