Date: Wed, 16 Dec 92 05:31:31    
From: Space Digest maintainer <digests@isu.isunet.edu>
Reply-To: Space-request@isu.isunet.edu
Subject: Space Digest V15 #555
To: Space Digest Readers
Precedence: bulk


Space Digest                Wed, 16 Dec 92       Volume 15 : Issue 555

Today's Topics:
                 Mars: "unusual" landforms, lat/long
                         NSSDC Data on CD-ROM

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Date: 7 Dec 92 15:42:02 GMT
From: Ed McCreary <mccreary@sword.eng.hou.compaq.com>
Subject: Mars: "unusual" landforms, lat/long
Newsgroups: sci.space

In article <s6R0uB2w165w@stycx.hacktic.nl> peter@stycx.hacktic.nl (Author) writes:
>You say that you distribute the original Viking images, how could I 
>obtain these.
>

Email the folks at the NSSDCA at request@nssdca.gsfc.nasa.gov and ask
for the list of CDROMs that are available.  The turnaround time
is only a day or so.


--
Ed McCreary                                               ,__o
mccreary@sword.eng.hou.compaq.com                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

------------------------------

Date: 7 Dec 92 15:37:08 GMT
From: Ed McCreary <mccreary@sword.eng.hou.compaq.com>
Subject: NSSDC Data on CD-ROM
Newsgroups: sci.space,alt.sci.planetary,alt.cd-rom

In article <Byronx.E1B@well.sf.ca.us> shiva@well.sf.ca.us (Kenneth Porter) writes:
>> Yes.  Keep in mind the images are the raw unprocessed data from Voyager.
>> The images are black and white.
>
>So where does the color come from that we see in the news? Is the
>original data in color and the CD just omits it, or is the color
>synthesized somehow?

The Voyager vidicon camera are B&W.  The imaging unit has a color wheel
with several different colored cels.  I believe there are nine different
filters.  The folks at the JPL Image Processing Lab (IPL) combine
the red, green, and violet images together to produce a color image.

Theorectically this is trivially done, but the three images are not
aligned.  Therefore, you must know the position and orientation of
the spacecraft relative to the subject of the picture in order to
align the three images and then combine them into a single picture.


>And does the retrieval software have all of the neat histogram stuff
>that we saw as the images came in live? It would be cool to play with
>false color on these images. [Coming soon to a rock video near you?]

IMDISP is released with the disk and is available on ames.arc.nasa.gov.
It has the capability to manipulate the histogram of the image and
used a pseudocolor palette.
>
>The lack of good marketing on this stuff demonstrates once again why
>the space program needs to be in private hands (unless it's Commodore!).

Note that these are meant for research purposes.  You can get nice
clean pictures from NASA easily.

--
Ed McCreary                                               ,__o
mccreary@sword.eng.hou.compaq.com                       _-\_<,
"If it were not for laughter, there would be no Tao."  (*)/'(*)

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End of Space Digest Volume 15 : Issue 555
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