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 archives.

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.

Begin with the U.S. Geological Survey's EROS Data Center, Global Land Information System--see GLIS.
Note: You may wish to open a second web-browser window, so you can read this page while you look at the GLIS page.

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.

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.

Click on "Index map" to see a map of the world. Next click on the eastern end of the Baltic Sea.

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).

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.

Click "Define area: Point," then click on Tallinn.
Move down the page. Highlight "Browse Availability: Yes," then click the "Submit Search" button.

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.

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 follows.

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.

When you have completed the form, click the "Submit Search" button.

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.

Click the "Color Composite (5,4,3)" option, then click the "Show me the Preview Image ..." 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.

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.

Access the United Nations Environment Programme GRID for the Baltic Sea region.

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.

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.

Visit Idrisi GIS at Clark University, Massachusetts.

Other GIS Data Sources

Canadian Centre for Remote Sensing (CCRS) homepage: Radarsat, Landsat and SPOT, quick-look image archive, and much more.
CCRS
Canadian National Altas Information Service (NAIS): Gateway to Canadian geography, maps, digital data, and services.
NAIS
European Space Agency (ESA): Ionia 1 km AVHRR global land data set.
ESA Ionia
German Remote Sensing Data Center (DGD): National infrastructure for earth observation, global ozone monitoring experiment, ENVISAT, X-SAR user kit, and more.
DGD
Landsat 7 homepage: Mission objectives and overview, schedule, organization, and news.
Landsat 7
National Aeronautics and Space Administration: NASA system-wide home page.
NASA homepage
NASA Earth Science Data Search and Order System (EOSDIS), "one-stop shopping" for all earth science data needs.
NASA EOSDIS
NASA Johnson Space Center (JSC), Imagery Services: Manned space photography, space-shuttle imagery.
NASA-JSC Imagery Services
NASA Jet Propulsion Laboratory (JPL): Earth and planetary imagery.
NASA-JPL
NASA Mission to Planet Earth (MTPE): Remote sensing, earth-system science.
NASA-MTPE
NOAA Defense Meteorological Satellite Program (DMSP): Data archive and image search using SPIDR.
DMSP
NOAA National Geophysical Data Center (NGDC), Geophysical On-Line Data (GOLD): Global digital elevation models, world geography.
NGDC-GOLD
NOAA Satellite Active Archive (SAA): AVHRR, Radarsat and other satellite systems.
SAA homepage
U.N. Environment Program, Global Resources Information Database (GRID-Arendal): Maps and datasets for Arctic, Scandinavian, Baltic, and European regions.
GRID-Arendal
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.
WDC homepage

GAGE Warsaw '98 Conference.