GAGE Workshop Data Search
This database search demonstration will be conducted during the computer workshop at the GAGE
conference at the Polish Geological Institute in Warsaw, Poland. Participants will gain
experience in conducting on-line searches for GIS and remotely sensed data at government
GIS Data Search for Estonia
For purposes of this demonstration, we will utilize Estonia, a country included in two
GAGE projects. Estonia is located at the eastern end of the Baltic Sea, Finland to the
north, Russia to the east, and Latvia to the south.
This webpage is the introduction to GLIS. Notice the table on the right; it is a listing of
all GIS and remotely sensed databases available at the EROS Data Center. Page down this listing
until you come to "Global 30-Arc-Second Elevation Data Set." Highlight this item, then click
the "Abstract" button. The abstract provides a brief overview of the database, what it
represents, how it was assembled, and how it can be utilized.
- Begin with the U.S. Geological Survey's EROS Data Center, Global Land Information System--see
- Note: You may wish to open a second web-browser window, so you can read this page while you look
at the GLIS page.
Now, click on the "back" button to return to the GLIS introduction. Next, click on
"Description" to view a detailed explanation of this database. After looking at the
description, return once again to the GLIS introduction, and click on the "Search"
button. The GLIS search page presents several search options.
The database is divided into tiles defined on the basis of latitude and longitude.
You are now looking at tile E020N90, which includes the region from the eastern Baltic to
the Ural Mountains. Click on the image to see a larger version. This tile could be downloaded
in compressed form via FTP (free) or ordered on CD-ROM ($10) or 8-mm cartridge tape ($15).
- Click on "Index map" to see a map of the world. Next click on the eastern end of the
Now return to the GLIS introduction. Select
"CORONA Satellite Photography" and view the abstract and description of this database, which
includes images from the Corona, Argon and Lanyard satellites series between
1960 and 1972. Move to the "Search" page and click the "Draw Area on Map" button. Manipulate
the map display by using pan, zoom in, and redraw functions, so that Estonia is displayed.
Zoom in until only Tallin and vicinity are displayed.
You will be presented with a table of entries for individual images. Pick one and click the "Detail" button.
You are given a locality map for the image, followed by the Meta Data Details in table format. Click
the "Show me the Preview Image ..." button. Browse images merely show the general location and cloud
cover within the scene; they are greatly degraded in quality from original photographs. Now move to the bottom
of this webpage, and notice medium/cost information ($14-18 each). The declassified satellite photo database
represents an excellent, low-cost source for high-resolution imagery.
- Click "Define area: Point," then click on Tallinn.
- Move down the page. Highlight "Browse Availability: Yes," then click the "Submit Search" button.
Return to GLIS and select
"Thematic Mapper Landsat Data" on the category table.
View the abstract and description to learn more about Landsat TM datasets.
Now you will carry out a search for available Landsat TM datasets. Click on the "Search" button, and you
are presented with several options for defining the geographic region of the search. In this case, you will
utilize the Landsat TM path/row position (see Landsat Worldwide Reference System). Fill in the search form as
|Browse availability ||Yes|
|Path ||188 to 189|
|Row ||019 to 019|
|Cloud cover ||0 to 1|
|Product distribution site ||10 years and older from EDC|
Note: Leave other boxes blank or accept default choices.
You will be presented with a table of entries for individual images. Pick a summer image and click the "Detail"
button. You are given a locality map for the image, followed by "Preview Image Display Options" and the Meta Data Details in table format.
- When you have completed the form, click the "Submit Search" button.
This false-color composite includes visible, near-infrared, and mid-infrared bands. Active vegetation appears green in this combination. Preview images show the general location, vegetation, water bodies, and cloud cover within the scene. Now move to the bottom of this webpage, and notice medium/cost information ($425 from EDC). This is the best source
for high-resolution, multispectral, satellite datasets.
- Click the "Color Composite (5,4,3)" option, then click the "Show me the Preview Image ..." button.
As this demonstration shows, the EROS Data Center is an outstanding source for various kinds
of GIS and remotely sensed databases covering the world. You will now continue to search for
GIS databases for Estonia at another data center.
Click on "Introduction" and read about the Baltic Drainage Basin Project. After glancing
at the introduction, click on "Maps" to view ready-made maps of the Baltic region. Select
a map and click the "VIEW" button. These maps may be downloaded in various graphical
formats. Note: these maps are finished images, not GIS databases.
- Access the United Nations Environment Programme GRID for the
Baltic Sea region.
Next click on "Idrisi data" to see more about GIS databases available in this popular format.
View the "metadata" file for one of the databases. These databases can be downloaded in
compressed format. Idrisi GIS databases may be manipulated and combined other GIS and
remotely sensed datasets for specialized analysis and products.
Idrisi GIS at Clark University,
Other GIS Data Sources
GAGE Warsaw '98 Conference.
- Canadian Centre for Remote Sensing (CCRS) homepage: Radarsat, Landsat and SPOT,
quick-look image archive, and much more.
- Canadian National Altas Information Service (NAIS): Gateway to Canadian geography, maps, digital data, and services.
- European Space Agency (ESA): Ionia 1 km AVHRR global land data set.
- German Remote Sensing Data Center (DGD): National infrastructure for earth observation,
global ozone monitoring experiment, ENVISAT, X-SAR user kit, and more.
- Landsat 7 homepage: Mission objectives and overview, schedule, organization, and news.
- National Aeronautics and Space Administration: NASA system-wide home page.
- NASA Earth Science Data Search and Order System (EOSDIS), "one-stop shopping" for all earth
science data needs.
- NASA Johnson Space Center (JSC), Imagery Services: Manned space photography,
NASA-JSC Imagery Services
- NASA Jet Propulsion Laboratory (JPL): Earth and planetary imagery.
- NASA Mission to Planet Earth (MTPE): Remote sensing, earth-system science.
- NOAA Defense Meteorological Satellite Program (DMSP): Data
archive and image search using SPIDR.
- NOAA National Geophysical Data Center (NGDC), Geophysical On-Line Data (GOLD):
Global digital elevation models, world geography.
- NOAA Satellite Active Archive (SAA): AVHRR, Radarsat and other satellite systems.
- U.N. Environment Program, Global Resources Information Database (GRID-Arendal):
Maps and datasets for Arctic, Scandinavian, Baltic, and European regions.
- U.S. Geological Survey, EROS Data Center homepage.
EROS Data Center
- World Data Centers (WDC), system-wide homepage: Global data bases for glaciology,
oceanography, paleoclimatology, etc.