| What
is a DOQQ? |
The answer to this question and other fundamental questions
about DOQQs can be found on the DOQQ
help page. |
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| When
will the entire state be covered?
-and-
What
areas of the state are covered? |
The entire state is covered as of December 16, 2001!
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| Why
are the DOQQs stored in the MrSid format? |
The MrSid format allows for the DOQQs to be compressed
greatly without sacrificing the visual quality of the
image. A 150 megabyte DOQQ can be compressed using 50
to 1 compression into a 3 megabyte MrSid file. To the
naked eye, there is very little change between the original
image and the MrSid image. |
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| What
programs can I use to view the MrSid files? |
There
are several ways to view a MrSid image. One way is to
use a GIS such as Intergraph Geomedia or ESRI Arcview
that has native MrSid support.
A second way is to download a MrSid plugin for a program
that you are using. Lizardtech, the maker of MrSid,
has plugins for Autodesk AutoCAD, Bentley MicroStation,
Adobe Photoshop, and others. Visit the Lizardtech site
at http://www.lizardtech.com
for more information.
The
third way is to use the MrSid standalone viewer. This
free viewer is downloadable from Atlas. Click
here to download from Atlas the standalone viewer
for Windows. For viewers for other operating systems
and for more advanced viewing tools for MrSid images,
visit the Lizardtech site at http://www.lizardtech.com.
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| How
can I convert a MrSid file into a TIFF file? |
Download the MrSid viewer from Lizard Tech. The viewer
has a function to write (export) a MrSid file to a TIFF
file. |
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| I
need a large number of DOQQs, and downloading the files
will take forever! How I can get a CD with the DOQQs that
I need? |
We are able to ship the 1998 DOQQs on DVDs for a fee. For more information, see our ordering page. |
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| How
can I get the unrectified imagery? |
The unrectified imagery can be ordered from the NASA
Regional Application Center at the University of Louisiana
at Lafayette. Contact Brent Yantis at yantisb@rac.usl.edu
for more information. |
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| Will
decompressing the MrSid file into a TIF file remove the
loss from compression? |
No, the loss has already occurred. Again, in most cases,
the loss is not noticable to the naked eye. Only those
people interested in performing detailed data analysis
should need the uncompressed files. |
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| When
will the DOQQs be updated? |
The
2004 DOQQ images are available on Atlas through the DOQQ 2004 Downloader. |
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