449
How Can You Use Geospatial Technology Online?
Sometimes the geospatial data comes available in a format called SDTS
(the Spatial Data Transfer Standard), a system established by the United
States government. The intent with SDTS was to place data in a “neutral” file
format rather than a software-specific one. Agencies like the USGS, NOAA,
and the Census Bureau utilize SDTS as the format for delivering their geospatial data to you. Software programs will often have a converter that enables
the import of data in SDTS format to a form directly readable by the software
(for instance, ArcGIS has a utility to import an SDTS DLG into a coverage for
you to use).
For some other examples of freely available geospatial software online,
check out Hands-on Application 15.6: Some Other Available Geospatial Technology Programs and Tools Online on page 450.
How Can You Use Geospatial Technology
Online?
Online resources are the quickest and easiest way to access geospatial data.
Whether you want to acquire archived satellite imagery or get the newest
updates for Google Earth, you can do everything via the Internet. The same
holds true with distributing your own data and information—setting up a
Web interface where your data can be used interactively is the way to go.
Posting parcel databases and DEMs for download will be of great aid to a
person with some geospatial knowledge, but other individuals may not know
You can access the National Map online at http://
nationalmap.gov/index.html—then select the option for National Map Viewers. From this new page,
choose the option to Open the Viewer. A new Web
page will open with the Viewer itself, the tool used
in accessing data via the National Map. The National
Map can be used to view available data—from the
Overlay options on the left side of map, you can select what layers to display. High-resolution imagery
can be accessed as an additional layer from the Imagery option on the right side of the map.
The layers you’re viewing in the National Map can
also be downloaded for use in GIS or other software
programs. First, search for an area of interest (for
instance, Reno, Nevada), then after the view of the
map changes, press the Download Data button in
the upper-right corner of the map. New download
options will appear that allow you to select the
extent of the area you want to download data for
(such as counties, congressional districts, or the extent of the view seen on the screen). Next, the data
layers available to download will be shown (including US Topo, structures, transportation, boundaries,
hydrography, land cover, elevation, and orthoimagery) as well as the formats these layers are available
in. Select the layers you want, then choose Add to
Cart and follow the remaining steps to download
your data (you will have to register with the USGS
to receive your data—they may send you an e-mail
with a link you can use to retrieve your data).
Hands-on Application 15.5
The National Map Viewer
SDTS the Spatial Data
Transfer Standard, a
“neutral” file format
for geospatial data,
allowing it to be
imported into various
geospatial software
programs.
How Can You Use Geospatial Technology Online?
Sometimes the geospatial data comes available in a format called SDTS
(the Spatial Data Transfer Standard), a system established by the United
States government. The intent with SDTS was to place data in a “neutral” file
format rather than a software-specific one. Agencies like the USGS, NOAA,
and the Census Bureau utilize SDTS as the format for delivering their geospatial data to you. Software programs will often have a converter that enables
the import of data in SDTS format to a form directly readable by the software
(for instance, ArcGIS has a utility to import an SDTS DLG into a coverage for
you to use).
For some other examples of freely available geospatial software online,
check out Hands-on Application 15.6: Some Other Available Geospatial Technology Programs and Tools Online on page 450.
How Can You Use Geospatial Technology
Online?
Online resources are the quickest and easiest way to access geospatial data.
Whether you want to acquire archived satellite imagery or get the newest
updates for Google Earth, you can do everything via the Internet. The same
holds true with distributing your own data and information—setting up a
Web interface where your data can be used interactively is the way to go.
Posting parcel databases and DEMs for download will be of great aid to a
person with some geospatial knowledge, but other individuals may not know
You can access the National Map online at http://
nationalmap.gov/index.html—then select the option for National Map Viewers. From this new page,
choose the option to Open the Viewer. A new Web
page will open with the Viewer itself, the tool used
in accessing data via the National Map. The National
Map can be used to view available data—from the
Overlay options on the left side of map, you can select what layers to display. High-resolution imagery
can be accessed as an additional layer from the Imagery option on the right side of the map.
The layers you’re viewing in the National Map can
also be downloaded for use in GIS or other software
programs. First, search for an area of interest (for
instance, Reno, Nevada), then after the view of the
map changes, press the Download Data button in
the upper-right corner of the map. New download
options will appear that allow you to select the
extent of the area you want to download data for
(such as counties, congressional districts, or the extent of the view seen on the screen). Next, the data
layers available to download will be shown (including US Topo, structures, transportation, boundaries,
hydrography, land cover, elevation, and orthoimagery) as well as the formats these layers are available
in. Select the layers you want, then choose Add to
Cart and follow the remaining steps to download
your data (you will have to register with the USGS
to receive your data—they may send you an e-mail
with a link you can use to retrieve your data).
Hands-on Application 15.5
The National Map Viewer
SDTS the Spatial Data
Transfer Standard, a
“neutral” file format
for geospatial data,
allowing it to be
imported into various
geospatial software
programs.