next up is the " Barycenter's "
do to changes in the read order of Celestia 1.7.0 for ssc and stc files
place the code for the barycenters at the TOP of your ssc file
i call mine " Solarsystem.SPICE.ssc"
next create a folder in the root Celestia install folder called " SpiceSolarSystem"
then add this to your "celestia.cfg"
-- for example --
Code: Select all
on about line 205
ExtrasDirectories [ "extras-standard" "extras" "/DATA/SUSE/SpiceSolarSystem/" ]
then in that folder make a folder called "data" , this is where the spice kernels go
them make a new text file called "Solarsystem.SPICE.ssc"
add the barycenters to that text file
Code: Select all
ReferencePoint "Mercury_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000 "
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp" # https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planets
Target "1"
Origin "0"
Period 0.25
BoundingRadius 1e10
}
}
ReferencePoint "Venus_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "2"
Origin "0"
Period 1
BoundingRadius 1e10
}
}
ReferencePoint "Earth_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "3"
Origin "0"
Period 1
BoundingRadius 1e10
}
}
ReferencePoint "Mars_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "4"
Origin "0"
Period 2
BoundingRadius 1e10
}
}
ReferencePoint "Jupiter_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "5"
Origin "0"
Period 12
BoundingRadius 1e10
}
}
ReferencePoint "Saturn_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "6"
Origin "0"
Period 12
BoundingRadius 1e10
}
}
ReferencePoint "Uranus_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "7"
Origin "0"
Period 12
BoundingRadius 1e10
}
}
ReferencePoint "Neptune_bary" "Sol"
{
Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
OrbitFrame { EclipticJ2000 { Center "SSB"}}
Visible true
Clickable true
SpiceOrbit
{
Kernel "de440.bsp"
Target "8"
Origin "0"
Period 12
BoundingRadius 1e10
}
}
now you will need to download the "de440.bsp" spice kernel, this is the barycenters for the planets
https://naif.jpl.nasa.gov/pub/naif/generic_kernels/spk/planetscopy or move the de440.bsp file to the new "data" folder"
to READ the data about it run the "brief" program on it
-- brief is a TERMINAL program , there is NO gui
make sure you change directory to the data folder , then run
"brief -c de440.bsp"
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brief -c de440.bsp
### you should get this output ###
BRIEF -- Version 4.0.0, September 8, 2010 -- Toolkit Version N0066
Summary for: de440.bsp
Bodies: MERCURY BARYCENTER (1) w.r.t. SOLAR SYSTEM BARYCENTER (0)
VENUS BARYCENTER (2) w.r.t. SOLAR SYSTEM BARYCENTER (0)
EARTH BARYCENTER (3) w.r.t. SOLAR SYSTEM BARYCENTER (0)
MARS BARYCENTER (4) w.r.t. SOLAR SYSTEM BARYCENTER (0)
JUPITER BARYCENTER (5) w.r.t. SOLAR SYSTEM BARYCENTER (0)
SATURN BARYCENTER (6) w.r.t. SOLAR SYSTEM BARYCENTER (0)
URANUS BARYCENTER (7) w.r.t. SOLAR SYSTEM BARYCENTER (0)
NEPTUNE BARYCENTER (8) w.r.t. SOLAR SYSTEM BARYCENTER (0)
PLUTO BARYCENTER (9) w.r.t. SOLAR SYSTEM BARYCENTER (0)
SUN (10) w.r.t. SOLAR SYSTEM BARYCENTER (0)
MERCURY (199) w.r.t. MERCURY BARYCENTER (1)
VENUS (299) w.r.t. VENUS BARYCENTER (2)
MOON (301) w.r.t. EARTH BARYCENTER (3)
EARTH (399) w.r.t. EARTH BARYCENTER (3)
Start of Interval (ET) End of Interval (ET)
----------------------------- -----------------------------
1549 DEC 31 00:00:00.000 2650 JAN 25 00:00:00.000
from the brief output you can get the needed information for the ssc file
for example
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MERCURY BARYCENTER (1) w.r.t. SOLAR SYSTEM BARYCENTER (0)
the w.r.t ( with respect to ) you get the " Origin "0" " entry
and from " 1549 DEC 31 00:00:00.000 2650 JAN 25 00:00:00.000 "
you get the :
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Beginning "1549 12 31 00:00:00.000"
Ending "2650 01 25 00:00:00.000"
dates
and that is it for the FIRST part , this is only for the barycenters
next will be the planets