TerraLook: Frequently Asked Questions
What is TerraLook?
TerraLook provides satellite images and some simple tools to view and use them.
It consists of two parts:
1) The image Collection. This is a set of georeferenced JPEG images on a
particular theme, plus some vector files that define the location of the images.
2) The Viewer/Toolkit. This is software that allows users to view and do useful
tasks with the Collection. Use of this software is not required, however, as the
images are in standard JPEG format that nearly any viewer or browser can
What defines a Collection?
Collections are based on themes. The most common theme is the protected areas of a country
or region, but any theme is acceptable. Examples include…a watershed,
subtropical World Heritage Sites, the world's 50 largest cities, the world's
volcanoes, and Puerto Rico.
What does your Viewer/Toolkit do?
First, it makes it easy to find the image you need by displaying the outline on
a map, so you can just click it to open the image. Then it allows roam and zoom,
viewing images from different epochs, creating and displaying your own overlays,
measurement of distance and area, and a variety of other tasks.
We should also point out that the development of this Viewer/Toolkit is not
being done by NASA/JPL, rather, it is a separate task being carried out by an
NGO called Ecollage, funded by several separate sponsors.
Do I have to use your Viewer/Toolkit?
No, you are free to view and interact with the data however you like, and
GIS-savvy users may not need the viewer. The Viewer/Toolkit now under
development is Open Source, based on a package called OpenEV. Because it is Open
Source, the source code is available and can be updated by any software
programmer who wants to change or add a capability.
Also, if you have ESRI ArcReader, we are experimenting with including a pmf file
(Published Map File… www.esri.com/arcreader) for each collection.
What happened to the original "Version 1" Viewer?
The original "Version 1" viewer, released in November 2004, is no longer being
distributed. Export regulations and some other constraints made it difficult to
freely distribute that viewer--constraints that are overcome with the Open
Why was it called the Protected Area Archive, and why did the name change to
The original idea was to include coverage only of protected conservation areas.
However, there are no constraints on coverage, and a "theme" can be whatever a
user would like it to be. TerraLook reflects the broader use of the data by
communities other than just conservation.
What Collections are available?
The available Collections are listed elsewhere on this site. However, these
collections may not be maintained, and they may gradually go out of date. In
that case, see the next question.
My area of interest is not in the available Collections list (or the collection
I want is out of date). How can I get a new Collection created?
Go to http://edc2.usgs.gov/terralook/. This is a USGS site that has now become
the permanent, operational home for TerraLook. There, you can create you own
What does it cost?
There is no charge for TerraLook Collections or the software.
Can I redistribute TerraLook Collections?
The Collections can be freely redistributed. The Open Source version
of the Viewer/Toolkit, available for free download from SourceForge.net,
utilizes the GNU Lesser General Public License and can be freely redistributed
if the license terms are followed.