Printable Version of Topic

Posted by: Yadgar Apr 16 2011, 10:43 AM

Hi(gh)!

I'm a raytracing (POV-Ray!) as well as an astronomy/space flight aficionado since many years and I have always admired those huge cylindrical maps of planets and moons stitched together from images gained by space probes. So I wonder how they are made - how to get exact information about each original image's viewing geometry and illumination phase angle, and what software to use to distort them appropriately to match the cylindrical map projection... can anyone around here give me some clues - or is it somewhat like a "trade secret"?

Currently, the "big thing" in making such maps is Mercury, next to Vesta, which will start to be mapped by the DAWN probe within the coming few months... I really would like to be among those who build their own planetary maps for modeling the Solar System!

See you in Khyberspace - www.khyberspace.de

Yadgar

Posted by: JohnVV Apr 17 2011, 05:12 AM

there are a few different ways
Some NOT free and VERY expensive
others are opensource gpl2 or 3

there are about as many ways as people doing it
some use MMPS
http://www.users.globalnet.co.uk/~arcus/mmps/
it is very handy
and the program "img2png "
http://www.unmannedspaceflight.com/index.php?showtopic=4979

others use a GIS program like SAGA-gis , or GRASS , --there are many

Myself i use ISIS3 from the USGS and NASA ( Linux ONLY !!!!!!)
http://isis.astrogeology.usgs.gov/index.html
along with Nip2/Vips
http://www.vips.ecs.soton.ac.uk/index.php?title=VIPS
then add in The Gimp
http://www.gimp.org/

also you will find that ( most here ) use Linux for there operating system .
some of the programs DO NOT work on Microsoft , other programs do .

Now ISIS3 dose take up A LOT and i DO MEAN A LOT of disk space
an example for Cassini
the isis install is small 762 Meg + 640 Meg of data
BUT
MRO for mars takes up 44 Gig of data
LRO ( what i am using right now ) is 24 Gig of data
and Cassini is ~ about 50 Gig ? if i recall right .

then there is the map . Just how BIG dose one want ??? a small 8192x4096 pixel ?
or a large 665536x32786 px map ( 6Gig 8 bit rgb image )
or like the LOLA data the LDEM_256 7.8 gig( 92160x46080 ) - for one file


you need to start by asking
what OS are you using ? if Windows vista or 7 then the list is a bit limited
if Linux then ....

now i think that Bjorn Jonsson and Phil Stooke use img2png and mmps most of the time ? but i might be wrong .
and those two DO work on Microsoft . ( though mmps dose need to be built on Mingw)

Posted by: djellison Apr 17 2011, 05:59 AM

Slightly semantic, but ISIS3 is also available for OSX. Indeed, that's the only platform I've ever used it on, and if you follow the instructions available on the ISIS3 website, it's actually not too hard to use. It is time, and hard drive, consuming, however.

Posted by: Yadgar Apr 17 2011, 09:57 AM

Hi(gh)!

Do they run under Windows XP or under Linux?



On my home system, I run Debian Linux (aptosid, kernel 2.6.38), so this would be no problem... but currently I'm staying with a friend who runs only Windows (XP and Vista), therefore I asked above...




8192 x 4096 would be nice for more distant planet views of my "PoVSolar" project... but when it comes to "aerial" or "pedestrian" views, it really should be



(you probably meant "65536 x 32768")

And how do I get the information on viewing geometry and illumination phase angle for each raw image? Are they stored within the original IMG format?

See you in Khyberspace!

Yadgar

Posted by: Phil Stooke Apr 18 2011, 08:14 PM

You don't need illumination data for this. The orientation is in a label file associated with each image in PDS.

Above all, you can't just press a few buttons and reproject a few images and be finished! Combining them into a good mosaic is an art. You have to be an artist above everything else.

Phil

Posted by: Yadgar Apr 18 2011, 09:51 PM

Hi(gh)!

O.k.... then, where can I find such PDS images on the web?



Yes, I'm pretty much aware that it takes a lot of scrupulous manual work, adjusting color levels and finding matching illuminations (if available)... but I just would give it a try!

See you in Khyberspace!

Yadgar

Posted by: djellison Apr 18 2011, 09:54 PM

You're going to need to do a lot of research yourself - it would take weeks of back-and-forth on a forum to cover what you're going to have to figure out. Fortunately, every single piece of information you're after is already on the web if you care to look for it. To get you started, try these places

Start here : http://pds.nasa.gov/

here : http://isis.astrogeology.usgs.gov/

And some great tutorials from Emily here : http://www.planetary.org/explore/topics/imaging/tutorials.html

Posted by: machi Apr 18 2011, 10:01 PM

And you probably need good (I mean best ) image converter - http://www.unmannedspaceflight.com/index.php?showtopic=4979&st=45&start=45

Posted by: JohnVV Apr 20 2011, 02:24 AM

while you are on MS windows xp img2png is a good program
also learning to use imagemagick ( on xp i mainly used MinGW-bash - a real terminal )
http://www.imagemagick.org/script/index.php
and GDAL
http://www.gdal.org/
( for Debian it should be in the repos )

and Time & research , then some more time .