PE&RS July 2015 - page 527

PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
July 2015
527
PROFESSIONAL
INSIGHT
What geographic features are in the program and why
are these important to data collection?
The MAF/TIGER system contains a variety of physical
features such as roads, railroads, rivers, lakes, and oth-
ers.  Physical features are important both as occasional
political boundaries and as navigation and visible ref-
erences for field workers.   MAF/TIGER also contains
non-visible political and statistical geography.  These
include things like city boundaries, tribal and state
boundaries as well as statistical entities such as census
tracts.    These various boundaries are critical for the
accurate tabulation and publication of the data.
Why were these geographic features essential to the
structure and growth of the database?
It was partly due to necessity and party due to design.
Of course, we had to keep track of new roads and sub-
divisions to update the TIGER maps used by enumera-
tors during fieldwork.  Likewise, we had to keep track
of boundary changes so that cities, counties and tribal
lands could have accurate counts after the decennial.
Also, TIGER visionaries like the late Bob Marx knew
we needed a way to generate millions of custom map
sheets to support our enumerators for the 1990 Census
and beyond.  As our country grows and changes, MAF/
TIGER grows along with it.
Why was the database set-up using layers and blocks?
How has this benefited the user?
In fact, TIGER was designed to be an integrated single
layer system.  Our TIGER/Line products were designed
to provide consumer information broken out by theme
or layer.  By downloading a single layer as a TIGER/
Line file, the user doesn’t have to deal with the entire
massive TIGER dataset. 
In order to maintain such a detailed and complex as-
sortment of geography, the MAF/TIGER system must
be able to relate various map primitives (points, lines,
and polygons) to one-another.  The topological business
rules in MAF/TIGER are extremely important for this.
These relationships are maintained in real-time and en-
sure we have consistency on a physical, political, and
statistic level.  So the MAF/TIGER system is much more
than a digital mapping system, it’s a topologically inte-
grated, geographic inventory of all political and statis-
tical geography in the United States and its territories.
One reason The US Census Bureau created the geospa-
tial framework in TIGER was for use in linking statistical
data in GIS. Who uses this data and what is it used for?
With TIGER, every tribal, state, and local government
has the opportunity to create its own geographic infor-
mation system with small-area census geographic data
using publicly available extracts of the TIGER data-
base. Everyone from oil companies locating pipelines to
forest managers mitigating wildfire hazards use TIGER
and census data.  From businesses tracking demograph-
ic trends to small business looking for new markets,
census data are everywhere.
Are there things the data could be used for but isn’t?
There is great potential with the Census API and our
new TIGERweb REST services.  These new tools are
providing instant access to the latest TIGER and cen-
sus data in fascinating ways.  Developers can now build
custom apps that combine these data on the fly in ways
we never could before.
TIGER sounds like a statisticians dream. Besides stat-
isticians, who else is using the information? 
Like so many other sources of information these days,
TIGER and Census data are finding their way into the
farthest corners of our society.  Open data and open
source tools are fueling a new generation of software
that leverages these data.  Traditional consumers like
city planners and businesses are still heavy users of
census data, but we’re now seeing software developers
leveraging our data in products that are integrated into
existing platforms.  With these tools, non-profits with
little financial ability can now consume and leverage TI-
GER and thousands of census variables with little or no
investment.
What lies in the future for TIGER?
I think you can expect to see MAF/TIGER data being
used in a wider variety of ways.  The USGS for example
will begin to use TIGER data as the road network for
the National Map starting this year.  Within the Cen-
sus Bureau, we are exploring new ways for updating the
roads and addresses to keep pace with our changing na-
tion.  We will certainly be expanding and solidifying our
current partnership efforts with tribal and local govern-
ments where we are incorporating local GIS data into
MAF/TIGER.
C
orrections
Ioannis Gitas and Giorgos Mallinis were the Guest Editors of
the June Special Issue on GEOBIA.
Assessment of Wildfire Risk in Lebanon Using Geographic
Object-Based Image Analysis, June 2015, benefited from
research supported by the National Science Foundation GSS
grant#1024413 to DM.
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