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SPICE orbits
http://forum.celestialmatters.org/viewtopic.php?f=9&t=540
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Author:  John Van Vliet [ Fri, 02-08-13, 21:19 GMT ]
Post subject:  SPICE orbits

while taking a break from the 86K EarthNight 32 bit data
NAIF updated a few things , mostly Pluto,Neptune,Uranus ,Saturn and the default naif kernel used "de721_full.bsp" for the planets

de721_full.bsp( 148.865 MB ) -- 1599 SEP 04 00:00:00.000 3000 MAR 03 00:00:00.000

or the 3.2 GIG "de431_full.bsp"
de431.bsp ( 3,230.288 MB)------ 13201 B.C. MAY 06 00:00:00.000 17191 MAR 15 00:00:00.000

--------------
For those who do not know this address already
the readme text file
ftp://naif.jpl.nasa.gov/pub/naif/generi ... readme.txt

ftp://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/

-- for leapseconds
ftp://naif.jpl.nasa.gov/pub/naif/generic_kernels/lsk/
ftp://naif.jpl.nasa.gov/pub/naif/generi ... if0010.tls

--and for orientation
ftp://naif.jpl.nasa.gov/pub/naif/generic_kernels/pck/
ftp://naif.jpl.nasa.gov/pub/naif/generi ... k00010.tpc

The bsp files for the planets
ftp://naif.jpl.nasa.gov/pub/naif/generi ... k/planets/

The bsp files for thesatellites
ftp://naif.jpl.nasa.gov/pub/naif/generi ... atellites/


so in keeping with Scientific accuracy
it might be a good idea to have a thread on
---- the 8 planets and their moons , with the minor planet "pluto" and it's menagerie of bodies in SPICE kernels ---
I am no expert but between all of us here a consensus "should" be able to be found


I have been using an edited version of the old "Barycenters.ssc" based layout by :"volcanopele"

so if there are no objections to this starting point
the beginning of this talk will be with just the Barycenter file

if we all agree that this is a good start then how about making a pined thread on just the settings only
--- updated for the smaller 148 meg kernel ( 3.2 Gig is big ,for the de431.bsp )

My version of the Barycenters.ssc ( Linux read order issues and bug require this to be named "1.Barycenters.ssc" )
Code:
ReferencePoint "Mercury_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame     { EclipticJ2000 { Center "SSB"}}
  Visible        true
  Clickable      true
  SpiceOrbit
  {
    Kernel       "de721_full.bsp"
    Target       "1"
    Origin       "0"
    Period        0.25
    BoundingRadius 1e10
  }
}

ReferencePoint "Venus_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame     { EclipticJ2000 { Center "SSB"}}
  Visible        true
  Clickable      true
  SpiceOrbit
  {
    Kernel       "de721_full.bsp"
    Target       "2"
    Origin       "0"
    Period        1
    BoundingRadius 1e10
  }
}

ReferencePoint "Earth_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame     { EclipticJ2000 { Center "SSB"}}
  Visible        true
  Clickable      true
 
 
  SpiceOrbit
  {
    Kernel       "de721_full.bsp"
    Target       "3"
    Origin       "0"
    Period        1
    BoundingRadius 1e10
  }
 
}


ReferencePoint "Mars_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame     { EclipticJ2000 { Center "SSB"}}
  Visible        true
  Clickable      true
  SpiceOrbit
  {
    Kernel       "de721_full.bsp"
    Target       "4"
    Origin       "0"
    Period        2
    BoundingRadius 1e10
  }
}


ReferencePoint "Jupiter_bary" "Sol"
{
 
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame { EclipticJ2000 { Center "SSB"}}
  Visible true
  Clickable true
  SpiceOrbit
  {
    Kernel "de721_full.bsp"
    Target "5"
    Origin "0"
    Period  12
    BoundingRadius 1e10
  }
 
}

ReferencePoint "Saturn_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame { EclipticJ2000 { Center "SSB"}}
  Visible true
  Clickable true
  SpiceOrbit
  {
    Kernel "de721_full.bsp"
    Target "6"
    Origin "0"
    Period 29.4577
    BoundingRadius 1e10
  }
}

ReferencePoint "Uranus_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame { EclipticJ2000 { Center "SSB"}}
  Visible true
  Clickable true
  SpiceOrbit
  {
    Kernel "de721_full.bsp"
    Target "7"
    Origin "0"
    Period 85
    BoundingRadius 1e10
  }
}

ReferencePoint "Neptune_bary" "Sol"
{
  Beginning      "1599 09 04 00:00:00.000"
  Ending         "3000 03 03 00:00:00.000"
 
  OrbitFrame { EclipticJ2000 { Center "SSB"}}
  Visible true
  Clickable true
  SpiceOrbit
  {
    Kernel "de721_full.bsp"
    Target "8"
    Origin "0"
    Period 166
    BoundingRadius 1e10
  }
}


then after this is Mercury,Venus,Earth,Mars,.....

Author:  John Van Vliet [ Fri, 02-08-13, 21:27 GMT ]
Post subject:  Re: SPICE orbits

an example for Mercury ( the rest of the solar system would be the same )
Code:

Replace "Mercury" "Sol"
{
  Texture "Map.image"
  Radius 2440
 
  Timeline
  [
  # Before Spice
  {
   
    BodyFrame { EquatorJ2000 { Center "Sol" } }
    Ending   "1599 11 04 00:00:00.000"  # add 2 months for orbit drawing
   
    CustomOrbit "vsop87-mercury"
    CustomRotation "iau-mercury"
  }
  # de721
  {
    OrbitFrame { EquatorJ2000 { Center "Sol/Mercury_bary"}}
    BodyFrame {  EclipticJ2000 { Center "Sol" } }
    Ending    "3000 01 03 00:00:00.000"  # less 2 month for orbit drawing
   
    # Visible true
    #Clickable true
   
    SpiceOrbit
    {
      Kernel "de721_full.bsp"
      Target "199"
      Origin "1"
      Period  0.25  # earth years
      BoundingRadius 1e10
    }
   
    #CustomRotation "iau-mercury"
    SpiceRotation
    {
      Kernel    [
      "pck00010.tpc"
      "naif0010.tls"
      ]
      Frame     "IAU_MERCURY"
     
    }
  }
 
  # After Spice
  {
   
    BodyFrame { EquatorJ2000 { Center "Sol" } }
    CustomOrbit "vsop87-mercury"
    CustomRotation "iau-mercury"
  }
 
  ]
 
  Albedo            0.06
 
}



mind you once we get into Jupiter and Saturn and the MOONS
this gets a bit complicated

Author:  t00fri [ Sat, 03-08-13, 7:02 GMT ]
Post subject:  Re: SPICE orbits

John,

a collection of Spice orbits is a great idea for celestia.Sci, which will actually come with the latest versions of the spice lib including 64bit compiles for 64 bit Linux.
In any case, your work will apply both for Celestia and celestia.Sci.

Fridger

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