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PostPosted: Sun, 21-03-10, 17:15 GMT 
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Hi all,

very recently, the new LOLA (Luna Orbiter Laser Altimeter) data of the LRO (Lunar Reconnaissance Orbiter) mission.

http://lunar.gsfc.nasa.gov/lola/

became available at the NASA PDS archive

http://pds-imaging.jpl.nasa.gov/portal/lro_mission.html
http://nssdc.gsfc.nasa.gov/nmc/experime ... 09-031A-04
http://pds-geosciences.wustl.edu/missio ... efault.htm

+++++++++++++++++++
or perhaps simpler from here
http://imbrium.mit.edu/DATA/LOLA_GDR/
++++++++++++++++++

In addition, a dedicated WEB site was opened, where Celestia-specific data are offered for download by the LOLA team, notably a 32k normalmap VT (virtual texture) set!

+++++++++++++++++++
http://imbrium.mit.edu/EXTRAS/CELESTIA/
+++++++++++++++++++

The VT's were obtained by the LOLA team with my Nmtools, as available from this CM site:

http://forum.celestialmatters.org/viewtopic.php?t=70

At last, we can enjoy a beautiful hires normalmap for the Moon besides the recent one from Kaguya-LALT, although the sampling density is still somewhat low. Therefore at the higher VT levels, one can clearly see the orbital ground tracks of LRO (stripe pattern). Of course we expect this to improve quite soon.

Unfortunately, the situation about a good quality basemap of the Moon is still unsatisfactory. The oldish Celementine data are full of nasty artefacts and also show a considerable non-linear pixel mismatch with the recent Kaguya and LOLA normalmaps.

Fortunately John Van Vliet went through a tedious remapping procedure recently and has now completed a nice matching base map!

http://forum.celestialmatters.org/viewtopic.php?t=361
http://www.shatters.net/forum/viewtopic.php?f=5&t=15726
EDIT: Being uploaded to the Motherlode right now

I thought, it might be useful to initiate a surely ongoing LRO-LOLA discussion in this forum with a few neat shots based on these new data. For now, I just show the Moon's appearance with a 8k non-VT texture set: the basemap is John VV's remapped 8k moon and the 8k normalmap, I redid myself using the official 64 pixel/degree data <=> 22.5k from

http://imbrium.mit.edu/DATA/LOLA_GDR/

Since the 16 bit PDS binary .IMG format refers to (little-endian) non-signed (0..65535) rather than signed 16 bit integers (-32768..32767), some code adaptation of my 'nm2pow2' tool was necessary: The single command-line for generating the 8k normalmap then reads
Code:
nm2pow2 23040 < LDEM_64.IMG | nm2half 16384 | nms 1753.784 16384 2.5 > nmout8k.png


with the 16bit read method in 'nm2pow2' adapted to unsigned 16bit integer input. Essentially, this amounts to re-declaring the row of 2 byte data from short to unsigned short and subtracting 0x8000 = 32768 to convert back to signed 16 bit for the remaining calculations.

But note :
------------
By this conversion, the zero level for the altitude shifted by a certain amount as follows:

According to the accompanying LBL file,
Code:
radius = DN * scale-factor + offset

offset = nominal Moon radius of 1737400 m = 1737.4 km
scale factor = 0.5
and DN (= Digital Number) is in meters, ranging within 0..65565


To convert to signed 2 byte integers within (-32768.. 32767), I had to redefine DN -> DN - 32768 (i.e short C++ type. Hence in order to retain the same radial distances, I have to redefine also
Code:
offset -> offset + scale factor * 32768 = 1753.784 km, i.e. the value I used above.

Then, correctly,
Code:
radius = DN * scale factor + offset = (DN - 32768) * scale factor + (offset + 32768 * scale factor)

where DN are the unsigned 2 byte input integers, that were internally converted. That hopefully explains the somewhat bigger Moon radius that is required in my 'nms' tool. I am planning to soon release a new version of the Nmtools accepting BOTH signed and unsigned 16 bit integer input.

Now, after these longish, yet hopefully somewhat instructive notes, let me display some nice shots obtained with only 8k non-tiled textures

A full view to start...

Image

++++++++++++++++++++++++++++
Throughout, click for bigger images!
++++++++++++++++++++++++++++

The Schroedinger crater at a zoom level that is almost too much for 8k textures

Image

Rather few craters with a familiar mountain range

Image

Wow!

Image

Finally, some Celestia.Sci images with colored, new galaxies for "dreaming" ;-)

A heavily cratered Moon with our neighbor LMC galaxy in the background:

Image

The Moon with the beautiful orange elliptical M60 and overlapping blue NGC 4674 galaxy in the background

Image

that look pretty similar in the SDSS photographic survey:
Image

And last not least, the Moon with the (elusive) Sagittarius dwarf galaxy that is about to collide with our Milky Way. See the peripheral cloud of globulars?

Image

Of course, I have turned up the galaxy brightness, to make that dwarf more conspicuous...

Enjoy,
Fridger


Last edited by t00fri on Mon, 22-03-10, 10:50 GMT, edited 1 time in total.

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 Post subject: re
PostPosted: Mon, 22-03-10, 0:26 GMT 
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the last of the Moon vt was uploaded to the ml last night
so in a few days it should be available
32 k map levels 0 to 5

this map was reworked based on the 5k kaguya map
but at first glance looks to line up well with the LRO Lola data

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 Post subject:
PostPosted: Mon, 22-03-10, 0:49 GMT 
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That's fine, John. Your 8k remapped Moon above also matched the LOLA data quite well. I added an editing note to my above post that your 32k texture is being uploaded to the ML.


Fridger


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 Post subject: re
PostPosted: Sun, 05-09-10, 4:02 GMT 
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there have not been many posts on this forum for a bit so a bit of an update
( i am mostly sure t00fri already knows this , but for the rest who might read )

the lola data was updated a little while back
BUT for the gdr data it was only a bug fix in some of the *.lbl files .There were some hacks needed to import them into isis3 - this was fixed

there were also some refinements added to the raw data points
if one wants to use the .tab data

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 Post subject: Re: re
PostPosted: Mon, 20-09-10, 10:13 GMT 
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John Van Vliet wrote:
there have not been many posts on this forum for a bit so a bit of an update
( i am mostly sure t00fri already knows this , but for the rest who might read )

the lola data was updated a little while back
BUT for the gdr data it was only a bug fix in some of the *.lbl files .There were some hacks needed to import them into isis3 - this was fixed

there were also some refinements added to the raw data points
if one wants to use the .tab data


Yes, thanks, John. Of course I am following what's going on there.

Fridger


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 Post subject: re
PostPosted: Mon, 20-09-10, 18:51 GMT 
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and a update to the last update
the lola page now has a monster 256ppd 7.9 Gig
92160x46080 map in 4 parts
a simple "emboss" on it for better viewing of the 16 bit data
the orig is in 16bit singed but with a very high offset & 0.5 meters scale
Code:
 SCALING_FACTOR        = 0.5

    OFFSET                = 1737400.


Image Image Image
Image Image

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