Using TIGER 2000
Dr. M Mustoe EOU, LaGrande, Oregon
Update 12 Jan 2004
The US Census Bureau has created digital data
for every county in the US, about
geographic features we encounter in our everyday lives: streets
and highways,
water bodies, major landmarks, railroads, and so forth. They have
also created data
about features we don't always think about: Congressional districts,
school
districts, traffic zones, census tracts, and so forth. For every
county in the US, there
are more than 20 such layers of data available for free download,
at the ESRI
TIGER 2000 site:
http://arcdata.esri.com/data/tiger2000/tiger_download.cfm
NEW Updated Information
Loging in at the site above is not
necessary to access this data. So step A of the Accessing the
TIGER data (below) is no longer needed. However you still
can register and still long in if needed. Selecting the state
from the US Map is the same.
Save the file to your hard drive: NOTE that file components
are NOT all inclusive...that is:
A shape file for Urban Centres is NOT available for Union County....However,
you can find one for Marion County . NOTE: like in the old
version of this page, the information data files you
may select from are catagorized by:
County OR you may Select by Layer
County...is just that...the county....but again not ALL the layers are avaialble for ALL the
counties.
Follow the directions below or more
appropriately perhaps the page information at the ESRI site.
The instructions on this page can help
you access and use the data.(You might find
it handy to print these instructions.) There are three major processes
to go through:
I.Accessing the TIGER
Data
II.Preparing the TIGER
Data
III.Using the TIGER Data
For further information and assistance on the Tiger on line data see:
http://www.esri.com/data/download/census2000_tigerline/index.html
A.Log in
1.Go to the ESRI TIGER 1995 site:
http://www.esri.com/data/online/tiger.
2.If you have not yet registered, you must do so before you can
download
data. Registration is free and only needs to be accomplished once.
3.After registering, you just use your email address to log on.
4.Note that the login page has some good information about the
TIGER
data, and includes links to web sites where you'll find extensive
documentation about the data.
B.Select your state.
You may either Tap on the map or choose from the pull-down state
picker.
C.Choose the desired "geography"
or "feature".
Decide if you want to download data of several kinds for a single
county, or
data of a single type for several counties. Choose either the
county or the data
type desired.
D.Select the desired elements.
Using the little check boxes at the left of each item, select
the desired items.
Note the size of each item, on the right. Everything will end
up packaged
together for downloading, but keep track of how much you will
be
downloading, and weigh this against how fast your download speed
is.
You're also limited to 20MB or 100 counties in a single download.
You might
want to break large downloads into two or more files, if you have
a lot of
material to download or your connection is slow. If you want to
receive all
the items, just Tap the checkbox for the topmost "all"
choice, and note how
large the file will be.
E.Tap the "generate" button.
When your selection is complete, scroll to the bottom and Tap
the
"GENERATE FILE NOW" button. This tells the server to
look at your
selection, package up a license file and a translation file plus
all the files you
have chosen, and create a single file for you to download. This
will take a
minute, so wait for the computer to send you your next instruction.
F.Tap the "download" button.
Once the server has prepared your data, it will give you the option
to
download the file. Tap the "DOWNLOAD DATA NOW" button.
At this
point, you should be thinking about where you want to store the
data so you
can find it.
G.Set the "target" storage site and
name.
Your browser will likely ask you what you want to name the file
as you are
saving it, and where you want to store it. Note carefully where
you want to
store it, such as
"C:\TIGER95\DOWNLOAD". Navigate to the desired drive
and directory,
and provide a sensible name, with a ".zip" file extension.
You might want to
name something according to the state and county, such as "tx_travis.zip",
or
state and features, such as "mn_railroads.zip". Begin
the saving process, and
wait for the download to be completed.
H.Choose more data or exit.
Once the file is downloaded, you can use your browser to go back
to
previous screens, even to choose a new state, and repeat the process.
Once
all your data are downloaded, you have completed the stage for
which the
browser is necessary.
Downloading the data is just the first step
in using TIGER data. Next you need to
do a two-step decompression, putting files in a place where you
can find them.
A.Self check: decompression software?
To prepare the TIGER data, you need to use file decompression
software that
can handle ".ZIP" files. If your computer does not have
this software, you can
download various versions as evaluation, free, or for purchase.
On PC's running Windows, a common choice is WinZip by Nico Mak:
http://www.winzip.com
On Macintoshes, a common choice is Expander by Aladdin Systems:
http://www.aladdinsys.com
B.Navigate to the downloaded ZIP file.
Using your Windows Explorer or Finder, navigate through your drives
and
directories to where you stored the ZIP file.
C.Double-Tap the downloaded ZIP file.
If your decompression software is properly installed, double-Taping
the file
should engage the decompression software. If, instead, your computer
asks
what you want to do with the file, choose to open the file using
the
decompression software.
D.Extract to the desired folder.
Indicate that you want to extract the files to a particular location.
Keep track
of where the files are being deposited. You may want to take this
time to
create and name a special new directory for storage, such as
"C:\TIGER95\EXTRACTED".
E.Look at the extracted files.
Navigate to the site holding your newly extracted files. You will
find
"DATALICENSE.HTML", "README.HTML", and one
or more ZIP files.
Each ZIP file contains the data for a single feature type for
a single county.
F.Double-Tap the ZIP file/s and extract to
the desired folder.
One by one, double-Tap and extract the individual ZIP files to
create the
actual shapefiles. Keep track of where these final files are being
deposited.
You may want to create and name a special new directory, such
as
"C:\TIGER95\FINAL". Note that some ZIP files will create
just a single
".DBF" table, while other ZIP files will create three
files, with extensions of
".DBF", ".SHP", and ".SHX".
G.Look at the README.HTML
There are many files in your final folder. The README.HTML file
will help
you understand which files provide which data. Note that each
filename (e.g.
"abc12345.shp") consists of three letters or numbers,
followed by the five
numbers representing the county FIPS code (two numbers for the
state, three
numbers for the county within the state), followed by the period
and
extension. The README.HTML file will identify which files relate
to specific
features or tables.
A.Engage ArcView software.
Begin ArcView or ArcVoyager. Since ArcVoyager is an ArcView application,
the descriptions below will apply to both. To use this data in
ArcVoyager,
you may choose any of the "Designing Global Adventures: Point
Me"
projects or "Creating New Worlds: Turn Me Loose" project;
you cannot
access the TIGER data within "Viewing World Snapshots: Show
Me." (You
may also use TIGER data within ArcExplorer, which requires a slightly
different set of procedures, that will not be covered here.)
B.Open the desired View.
In ArcView or ArcVoyager, either create a new view or work with
a
pre-existing view. If you are using a pre-existing view, notice
if the view is in
"decimal degrees" or is "projected". This
will help you anticipate what your
new data should look like.
C.Add the desired theme.
Add themes in the standard fashion, navigating to where you have
stored the
data and making sure that you are seeing "Feature Data Source"
files (rather
than "Image Data Source" files).
D.Zoom to the new theme and turn it on.
Make your new theme/s active and Tap the "Zoom to Active
Theme"
button. This will bring you to the scale of the county (counties)
added. Tap
the checkbox to the left of the theme name to turn it on.
E.Identify features.
Use the "Identify" tool to see information about single
features in each theme.
The fields listed in the Identify window will be fields you can
use for
classification and symbolization purposes.
F.Add data tables for BLK, GRP, TRT.
The "block", "block group" and "tract"
shapefiles do not carry much data.
Instead, there are separate data tables that can be joined to
the shapefiles.
Add the data tables "B90xxxxx.dbf", "G90xxxxx.dbf",
and "T90xxxxx.dbf"
and join these to the attribute tables for the "BLKxxxxx.shp",
"GRPxxxxx.shp", and "TRTxxxxx.shp" files.
In each case, use the field
named "KEY" to join the new data to the proper features
in the attribute
tables.
G.Classify and symbolize the data.
Use standard procedures for choosing the symboliation style for
each feature.
H.Speed up draw times for streets, blocks,
and streams.
Because there are often well over 1000 records in the streets,
blocks, and
streams layers, it may help to speed their draw times by creating
a "Spatial
Index." (NOTE: This option is not available using ArcVoyager
Special
Edition.)
1.Make the desired theme active.
2.Open the theme table.
3.Tap the "SHAPE" field at the far left, darkening the
header.
4.From the "FIELD" menu, choose "Create Index".
If this choice is
greyed out and "Remove Index" is listed, the index already
exists, so
just exit this menu.