SPICE

[ElChristou]

Tx Sym, the only problem is that I have no idea on how to set a build with Spice on osX...

[cartrite]

I ran into a little problem with spice that I commented on here.
http://www.celestiaproject.net/forum/viewtopic ... 8193#78193
The problem I'm refering to is highlighted in red.

[symaski62]

ftp://naif.jpl.nasa.gov/pub/naif/MRO/kernels/spk/

=> spk_psp_rec00772_00766_01042_p-v1.bsp
=> spk_psp_rec00772_00766_01042_p-v1.bsp.lbl

START_TIME=2006-09-25T04:35:00.000
STOP_TIME=2006-10-16T16:55:00.000

||
\/
C:\Program Files\Celestia\extras\MRO\

=> MRO.ssc

C:\Program Files\Celestia\extras\MRO\data

=> spk_psp_rec00772_00766_01042_p-v1.bsp
=> spk_psp_rec00772_00766_01042_p-v1.bsp.lbl

Code: Select all

Barycenter "Spice_Sun" "Sol"
{
   Color [ 1 1 1 ]

   Radius 100000


   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "0"
                Origin "10" 

      BoundingRadius 1e10
   }
}

Barycenter "earth BARYCENTER" "Sol/Spice_Sun"
{
   Color [1 1 1]
   Radius 100

   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "3"
                Origin "0" 

      BoundingRadius 1e10
   }
}

"Spice_earth" "Sol/Spice_Sun/earth BARYCENTER"
{
   Color [0 1 0]
   Radius 6000

   OrbitReferencePlane "ecliptic"
   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "399"
                Origin "3" 

      BoundingRadius 1e10
   }

}

"Spice_moon" "Sol/Spice_Sun/earth BARYCENTER"
{
   Color [0 1 0]
   Radius 6000

   OrbitReferencePlane "ecliptic"
   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "301"
                Origin "3" 

      BoundingRadius 1e10
   }

}

Barycenter "mars_BARYCENTER" "Sol/Spice_Sun"
{
   Color [1 1 1]
   Radius 100

   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "4"
                Origin "0" 

      BoundingRadius 1e10
   }
}

"Spice_mars" "Sol/Spice_Sun/mars_BARYCENTER"
{
   Color [0 1 0]
   Radius 3396

   OrbitReferencePlane "ecliptic"
   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "499"
                Origin "4" 

      BoundingRadius 1e10
   }

}


"Spice_MRO" "Sol/Spice_Sun/mars_BARYCENTER"
{
   Color [1 1 1]
   Radius 1

   OrbitReferencePlane "ecliptic"
   SpiceOrbit
   {
      Kernel "spk_psp_rec00772_00766_01042_p-v1.bsp"
               Target "-74"
                Origin "4" 

      BoundingRadius 1e10
   }

}

voila

[cartrite]

symaski62,
After staring at your post long enough , I finally realized it's meaning, I think. It seams like a lot of work for such a
small mission window. If you download all the files for the mission and use spkmerge to combine them you could reconstruct the whole mission.

Code: Select all

1.   wget ftp://naif.jpl.nasa.gov/pub/naif/DEEPIMPACT/kernels/lsk/naif0008.tls
   wget ftp://naif.jpl.nasa.gov/pub/naif/DEEPIMPACT/kernels/spk/dii_preenc174_nav_v1.bsp
   wget ftp://naif.jpl.nasa.gov/pub/naif/DEEPIMPACT/kernels/spk/dif_preenc174_nav_v1.bsp
   wget ftp://naif.jpl.nasa.gov/pub/naif/DEEPIMPACT/kernels/spk/di_tempel1_ssd_v1.bsp
   wget ftp://naif.jpl.nasa.gov/pub/naif/DEEPIMPACT/kernels/spk/di_finalenc_nav_v3_to2006048.bsp


Code: Select all

2. Create a merge file. DI-merge
   leapseconds_kernel  = /your-kernel-folder/naif0008.tls
   spk_kernel          = /your-kernel-folder/deep-impact.bsp
   source_spk_kernel   = /your-kernel-folder/dii_preenc174_nav_v1.bsp
   source_spk_kernel   = /your-kernel-folder/dif_preenc174_nav_v1.bsp
   source_spk_kernel   = /your-kernel-folder/di_tempel1_ssd_v1.bsp
   source_spk_kernel   = /your-kernel-folder/di_finalenc_nav_v3_to2006048.bsp
3. Run spkmerge with DI-merge

Code: Select all

4. SSC file :
"Tempel1" "Sol"
{
   Class "comet"
   Mesh "tempel1.3ds"
   Texture "comet2.jpg"
   Radius 178
   Albedo 0.7
   SpiceOrbit
   {
       Kernel "deep-impact.bsp"
       Target "1000093"
       Origin "10"
            BoundingRadius 2
            Period 5.51615
 
       Beginning "2005 1 12 19:23:32.068"
       Ending "2006 1 20 00:00:00"
   }
}

"Deep-Impact" "Sol"
{
   Class "spacecraft"
   Mesh "DeepImpact3.3ds"
   Radius 0.001
   Beginning "2005 1 12 19:23:32.068"
   Ending "2009 1 15 00:05:00.000"
   Albedo 0.7
   SpiceOrbit
   {
       Kernel "deep-impact.bsp"
       Target "-140"
       Origin "10"
            BoundingRadius 2
 
       Beginning "2005 1 12 19:23:32.068"
       Ending "2009 1 15 00:05:00.000"
   }
   Obliquity  180
}

"Impactor" "Sol"
{
   Mesh "DI-Impactor.3ds"
   Radius 0.001
   Beginning "2005 1 12 19:23:32.068"
   Ending "2005 7 4 05:45:43.183"
   Albedo 0.7
   SpiceOrbit
   {
       Kernel "deep-impact.bsp"
       Target "-70"
       Origin "10"
            BoundingRadius 2
 
       Beginning "2005 7 3 06:16:04.184"
       Ending "2005 7 4 05:45:43.183"
    }
   Obliquity  90
   RotationPeriod 0.00000000000000000000001
}

The Cspice toolkit could also probally be used to weed out all the comments in the bsp files to decrease their size. I'm looking into that.

I'm not sure what Chris's changes will look like but I think this would probally still work.
I still have to use the older versions of spiceorbit.cpp spiceorbit.h parseobject.cpp because when the program starts, spkgps_c gets an error for insuffiecnt data for the spacecrafts in the present time period, and no matter what I set the date to after that, they are never loaded .

[chris]

I just checked in a change that requires Beginning and Ending fields to define the valid range of a SPICE orbit. I don't really like this very much--Beginning and Ending also need to be specified for the body that uses the SPICE orbit. Unfortunately, I'm not having much luck getting SPICE to tell me what the valid range of its data, and this data really has to be in the Celestia orbit structure.

I'll keep searching for a more elegant solution, but in the mean time, Beginning and Ending are necessary for some complex SPICE scenarios.

--Chris

[phoenix]

chris,

after your last changes i'm getting the following error compiling the cvs:

Code: Select all

celestiacore.cpp(2863) : error C2039: 'getRotationElements' : is not a member of  'Body'
        ..\celengine\body.h(81) : see declaration of 'Body'

since I don't know what type or function getRotationElements() should be you're the only one who can fix this

[chris]

chris,

after your last changes i'm getting the following error compiling the cvs:

Code: Select all

celestiacore.cpp(2863) : error C2039: 'getRotationElements' : is not a member of  'Body'
        ..\celengine\body.h(81) : see declaration of 'Body'

since I don't know what type or function getRotationElements() should be you're the only one who can fix this

It's fixed now. I checked in some changes in two parts, and both you and Selden synched right in between them

--Chris

[cartrite]

chris,

after your last changes i'm getting the following error compiling the cvs:

Code: Select all

celestiacore.cpp(2863) : error C2039: 'getRotationElements' : is not a member of  'Body'
        ..\celengine\body.h(81) : see declaration of 'Body'

since I don't know what type or function getRotationElements() should be you're the only one who can fix this

It's fixed now. I checked in some changes in two parts, and both you and Selden synched right in between them

--Chris

Well I'm batting 500. The spice mission I did for deep impact works "right out of the box" Didn't change a thing. The Near mission has some problems though but I was hacking that to get it to work with the old code. So who knows what I did. This is with 64bit Suse. Suse 10 is using a beta version of the spice library so....... Haven't tried the 32bit system or windows yet. Not bad.
cartrite

[cartrite]

A question,
If you are using Spice orbits, the Deep Imact mission for example, should the solar system barycenter affect body and spacecraft positions if it is used or not used? The Impactor and Temple1 change positions in the solar system depending on which origin is used in the nearstars.stc. They don't change positions relative to each other though. Isn't the origin data supplied in the kernels?
cartrite

[selden]

You have to use the correct combinations of ephemerides.

If you want to plot positions relative to the barycenter, you have to use ephemerides that have coordinates measured relative to the barycenter. Otherwise they'll certainly be drawn in the wrong locations

[cartrite]

Brief. Version: 2.3.1 (SPICE Toolkit N0060)


Summary for: /home/cartrite/bin/09202006/cspice/exe/di_finalenc_nav_v1.bsp

Body: DEEP IMPACT IMPACTOR SPACECRAFT (-70)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 04 05:46:17.184

Body: DEEP IMPACT FLYBY SPACECRAFT (-140)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:45:34.183

Body: TEMPEL 1 (1000093)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:46:38.183


Summary for: /home/cartrite/bin/09202006/cspice/exe/di_finalenc_nav_v3.bsp

Body: DEEP IMPACT IMPACTOR SPACECRAFT (-70)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 04 05:46:38.184

Body: DEEP IMPACT FLYBY SPACECRAFT (-140)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:45:34.183

Body: TEMPEL 1 (1000093)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:46:38.183


Summary for: /home/cartrite/bin/09202006/cspice/exe/di_finalenc_nav_v3_
to2006048.bsp

Body: DEEP IMPACT IMPACTOR SPACECRAFT (-70)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 04 05:46:38.184

Body: DEEP IMPACT FLYBY SPACECRAFT (-140)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:45:34.183

Bodies: TEMPEL 1 (1000093)
1000093001*
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.183 2005 JUL 05 05:46:38.182

Body: 8999999
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JUL 03 06:16:04.184 2005 JUL 05 05:46:38.183


Summary for: /home/cartrite/bin/09202006/cspice/exe/dif_preenc174_nav_v1.bsp

Body: DEEP IMPACT FLYBY SPACECRAFT (-140)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JAN 12 19:23:32.068 2009 JAN 15 00:05:00.000

Bodies: MERCURY BARYCENTER (1)
VENUS BARYCENTER (2)
EARTH BARYCENTER (3)
MARS BARYCENTER (4)
JUPITER BARYCENTER (5)
SATURN BARYCENTER (6)
URANUS BARYCENTER (7)
NEPTUNE BARYCENTER (8)
PLUTO BARYCENTER (9)
SUN (10)
MERCURY (199)
VENUS (299)
MOON (301)
EARTH (399)
MARS (499)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JAN 12 19:23:32.068 2009 JAN 15 00:05:00.000

Body: BOETHIN (1000004)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 MAY 09 00:00:00.000 2009 JAN 15 00:05:00.000

Body: TEMPEL 1 (1000093)
Start of Interval (ET) End of Interval (ET)
-------------------------------- --------------------------------
2005 JAN 12 19:23:32.068 2006 JAN 20 00:00:00.000

di-kernels.txt

###\begindata

PATH_VALUES = ( 'extras/near/data' )
PATH_SYMBOLS = ( 'P' )

KERNELS_TO_LOAD = (
'$P/di_tempel1_v01.tpc',
'$P/di_v17.tf',
'$P/deep-impact.bsp'
)
\begintext

Contents of deep-impact.bsp

leapseconds_kernel = /home/cartrite/bin/09202006/cspice/exe/naif0008.tls
spk_kernel = /home/cartrite/bin/09202006/cspice/exe/deep-impact.bsp
source_spk_kernel = /home/cartrite/bin/09202006/cspice/exe/dii_preenc174_nav_v1.bsp
source_spk_kernel = /home/cartrite/bin/09202006/cspice/exe/dif_preenc174_nav_v1.bsp
source_spk_kernel = /home/cartrite/bin/09202006/cspice/exe/di_tempel1_ssd_v1.bsp
source_spk_kernel = /home/cartrite/bin/09202006/cspice/exe/di_finalenc_nav_v3_to2006048.bsp

di.ssc

"Tempel1" "Sol"
{
Class "comet"
Mesh "tempel1.3ds"
Texture "comet2.jpg"
Radius 178
#Beginning Beginning "2005 1 12 19:23:32.068"
#Ending "2006 1 20 00:00:00"
Albedo 0.7
SpiceOrbit
{
Kernel "deep-impact.bsp"
Target "1000093"
Origin "10"
BoundingRadius 2
Period 5.51615

Beginning "2005 1 12 19:23:32.068"
Ending "2006 1 20 00:00:00"
}
}

"Deep-Impact" "Sol"
{
Class "spacecraft"
Mesh "DeepImpact3.3ds"
Radius 0.001
Beginning "2005 1 12 19:23:32.068"
Ending "2009 1 15 00:05:00.000"
Albedo 0.7
SpiceOrbit
{
Kernel "deep-impact.bsp"
Target "-140"
Origin "10"
BoundingRadius 2
#Period 5.51615

Beginning "2005 1 12 19:23:32.068"
Ending "2009 1 15 00:05:00.000"
}
#Orientation [ 270 1 0 0 ]
Obliquity 180
#SampledOrbit "DeepImpact.xyz"
}

"Impactor" "Sol"
{
Mesh "DI-Impactor.3ds"
Radius 0.001
Beginning "2005 1 12 19:23:32.068"
#Beginning "2005 7 3 06:16:04.184" #06:00:00 UTC Jul 03 2005
Ending "2005 7 4 05:45:43.183" #06:01:04 UTC Jul 04 2005
Albedo 0.7
SpiceOrbit
{
#Kernel "di-kernels.txt"
Kernel "deep-impact.bsp"
Target "-70"
Origin "10"
BoundingRadius 2
#Period 500.51615

Beginning "2005 7 3 06:16:04.184"
#Ending "2005 7 5 05:46:38.183"
Ending "2005 7 4 05:45:43.183"
}
#SampledOrbit "DeepImpact-Impactor.xyz"
#Orientation [ 270 1 0 1 ]
Obliquity 90
RotationPeriod 0.00000000000000000000001
}

[chris]

A question,
If you are using Spice orbits, the Deep Imact mission for example, should the solar system barycenter affect body and spacecraft positions if it is used or not used? The Impactor and Temple1 change positions in the solar system depending on which origin is used in the nearstars.stc. They don't change positions relative to each other though. Isn't the origin data supplied in the kernels?

The center that you use for the SPICE orbit should match the one you use for the object. If the center for the SPICE orbit is the solar system barycenter, then the object should have it's orbit center (defined by either its parent object or OrbitBarycenter) set to the solar system barycenter. A single SPICE kernel does not always contain enough information to compute the position of an object relative to the solar system barycenter. For example, the kernel for the NEAR mission had the trajectory of the problem split into several segments, with positions relative a different object in each segment: Earth, the Sun, Mathilde, or Eros. But, by loading all of the right kernels, I could get SPICE to give me a heliocentric position of NEAR for the entire mission.

--Chris

[cartrite]

"Tempel1" "Sol"

So this is controling the origin. Accounts for the change in positions. Did you try spk-merge yet? Makes things a lot more orginized.
Chris wrote:

For example, the kernel for the NEAR mission had the trajectory of the problem split into several segments, with positions relative a different object in each segment: Earth, the Sun, Mathilde, or Eros. But, by loading all of the right kernels, I could get SPICE to give me a heliocentric position of NEAR for the entire mission.

I remember that vaugely. It's been a while so I got to refresh my memory a little more. I think I may have taken a few of the kernels out of the merge. Of the three I did, Near is the only one that needs work. I compiled the 32bit on Suse 9.2 and Galileo was right on too. Batting .667
cartrite

[Malenfant]

A question,
If you are using Spice orbits, the Deep Imact mission for example, should the solar system barycenter affect body and spacecraft positions if it is used or not used? The Impactor and Temple1 change positions in the solar system depending on which origin is used in the nearstars.stc. They don't change positions relative to each other though. Isn't the origin data supplied in the kernels?

The center that you use for the SPICE orbit should match the one you use for the object. If the center for the SPICE orbit is the solar system barycenter, then the object should have it's orbit center (defined by either its parent object or OrbitBarycenter) set to the solar system barycenter. A single SPICE kernel does not always contain enough information to compute the position of an object relative to the solar system barycenter. For example, the kernel for the NEAR mission had the trajectory of the problem split into several segments, with positions relative a different object in each segment: Earth, the Sun, Mathilde, or Eros. But, by loading all of the right kernels, I could get SPICE to give me a heliocentric position of NEAR for the entire mission.

--Chris

All this doesn't affect stellar/planetary systems outside our own, does it? I mean, would we have to define exact system barycentres for other planetary systems? Or can we stick to using the star as the barycentre for those?

[chris]

All this doesn't affect stellar/planetary systems outside our own, does it? I mean, would we have to define exact system barycentres for other planetary systems? Or can we stick to using the star as the barycentre for those?

Using a barycenter is completely optional. You could define one and make your system slightly more realistic, but I don't imagine that it matters for most fictional systems (unless it's for modeling the systems from systemic--http://www.oklo.org)

--Chris

[CAP-Team]

I've been looking for an ephemeris file for the New Horizons spacecraft to Pluto. I'm looking for a SPK kernel (.bsp).
Does anyone know where I can find this data? (I know it's on the horizons system, but I have no clue what parameters I should use to get the data I want).
NASA's space simulator can simulate New Horizons so I guess the data is somewhere available.

[selden]

Unfortunately, Horizons generates Spice kernels only for minor planets, not for spacecraft. However, it's relatively straight forward to translate Horizon's vector output into Celestia's xyz trajectory format. A template that I use for obtaining heliocentric vector tables is available at http://www.lepp.cornell.edu/~seb/celest ... mplate.txt

You'll probably have to contact the New Horizons staff to get a current Spice kernel.

[CAP-Team]

Hi, I downloaded the latest CVS from Phoenix (purebytes.de), created the spice-cassini.ssc file and downloaded a .bsp file from the NAIF FTP site, but I can't select the spice-cassini object?

Am I missing something here?
The .ssc and bsp file are in the extras folder.
I also put in a beginning and end date in the ssc file.

[selden]

The bsp file has to go into the Addon's data directory.

e.g.
extras/MySpice/myspice.ssc
extras/MySpice/data/myspice.bsp

Please be sure to read through this entire thread.
I really don't feel like writing the same things all over again.

[selden]

Sorry, I was thinking this was a different thread.

For the travails in getting Spice kernels to work, please read the thread
http://www.celestiaproject.net/forum/viewtopic.php?t=11059&