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EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 01:12
by selden
There are many more things that could be done to it, but I decided enough is enough. For now.

This Addon includes a medium resolution model of one of the EVLA telescopes and uses many low-resolution models to show the extent of the array.

http://www.lepp.cornell.edu/~seb/celestia/vla.html
evla.jpg


The EVLA Zip file is 4.1 MB, expanding to about 12 MB when installed.

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 01:34
by selden
Warning: the SSC files sometimes are loaded in the wrong order on Linux systems, and maybe on Macs.
If things don't look right, and the log shows reference frame errors, then combine the three SSC files into a single SSC and eliminate the originals.
e.g.

Code: Select all

cat 1.ssc 2.ssc 3.ssc > 123.ssc
rm 1.ssc 2.ssc 3.ssc


Please let me know if you have to do this.

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 02:04
by Cham
Thanks a lot Selden.

However, is it possible to publish a simpler version, with just a single "high resolution" model, without any other models (low res), and without the textured base ?

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 02:48
by selden
But.. but.. but.. You were the one who wanted to see the different configurations!
Cham wrote:Also, a version with several radiotelescopes would be nice (array of radiotelescopes)...

The higher-resolution model itself accounts for most of the size of the Addon: about 8 of the 12 MB.
You can use the same SSC as I posted for the original model, but add a section for the pedestal.The other mesh names are the same as before. I just now verified that it works.

Code: Select all

#evla telescope model
# modified to place the telescope on the surface of Celestia's sphere
# and to have a fixed orientation.

# Copyright (c) 2011 s.ball

# location of VLA taken from
# http://www.vla.nrao.edu/genpub/overview/
# Location: Plains of San Agustin, west of Socorro, New Mexico.
# latitude = 34°04'43.497" north = 34.0787492
# longitude = 107°37'03.819" west = 107.6177275
# elevation = 2124 m (6970 ft)
# Size:
#    Each antenna: 25 m (82 ft) in diameter, 230 tons.

# the position of the telescope

SurfaceObject "vla-01" "Sol/Earth"
{
   Class "invisible"
   Radius   0.0125

   FixedPosition { Planetographic [ -107.6177  34.0787  0.011]}
   FixedRotation {}
}


# the telescope dish
"vla-01-reflector" "Sol/Earth/vla-01"
{
   Class "component"

   Mesh "vla-dish.cmod"
   Radius   0.013

   NormalizeMesh false
   MeshScale 0.000055

   OrbitFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedPosition [ 0 0 0 ]

   BodyFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedRotation {Inclination -45}
}

# the yoke carrying the dish

"vla-01-yoke" "Sol/Earth/vla-01"
{
   Class "component"

   Mesh "vla-yoke.cmod"
   Radius   0.0125

   NormalizeMesh false
   MeshScale 0.000055 # arbitrary paper size

   OrbitFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedPosition [ 0 0 0 ]

   BodyFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedRotation {}
}

# the pedestal supporting the yoke

"vla-01-pedestal" "Sol/Earth"
{
   Class "component"

   Mesh "vla-pedestal.cmod"
   Radius   0.0125

   NormalizeMesh false
   MeshScale 0.000055 # arbitrary paper size

   OrbitFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedPosition [ 0 0  0 ]

   BodyFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedRotation {}
}

"vla-01-base" "Sol/Earth"
{
   Class "component"

   Mesh "vla-base.cmod"
   Radius   0.0125

   NormalizeMesh false
   MeshScale 0.000055 # arbitrary paper size

   OrbitFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedPosition [ 0 0  0 ]

   BodyFrame { BodyFixed { Center "Sol/Earth/vla-01"}}
   FixedRotation {}
}



p.s. oops. minor bug: change inclination to -45 so the dish tilts in the correct direction relative to the yoke. I've fixed it above.

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 02:53
by Cham
Ok thanks again.

It's just that the full version with all the dishes is pretty heavy on my system. It's too slow for actual use in the classroom, using my small portable computer (13" MacBook Pro with NVidia 320M).

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 03:14
by selden
On my system eliminating everything else by using only the SSC above doubles the framerate, from about 12fps to about 24fps. 2x might or might not help enough for you.

How much improvement do you see?

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 03:16
by Cham
Selden,

I changed the base. I think it's better this way. However, both bases need a small correction : there's a visible hole on the side which needs to be closed (see the picture below). Also, I strongly suggest that you add some normal map texture to the rocks on the base.

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 03:27
by Cham
Okay, I already added a normalmap texture to the base, it's MUCH better looking ! I'll send you the texture and modified mesh (however, it still needs a patch to the hole on the other side).

I also smoothed the dish, but there are some artifacts near the center...
base2.jpg

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 03:37
by selden
Cham,

The dish is made of multiple panels which are not perfectly smooth.
See the upgrade pictures at http://www.aoc.nrao.edu/~pharden/VLA_PI ... ix_002.htm

Re: EVLA: Expanded Very Large Array (of radio telescopes)

Posted: 19.04.2011, 03:43
by Cham
Hmmm, the curved dish appears to be smooth to me, (except the visible lines). Well, this is just a detail.

Nice pictures, by the way !