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Issue with Celestia Spice... or ... ???
http://forum.celestialmatters.org/viewtopic.php?f=18&t=680
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Author:  John Van Vliet [ Fri, 18-07-14, 20:38 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

got it
this is turning into a bit of a conundrum .

Author:  fenerit [ Sat, 19-07-14, 1:13 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

Jupiter for the year 2200 AD
Attachment:
jupiter_2200.png
jupiter_2200.png [ 157.19 KiB | Viewed 5140 times ]

While for set altitude = 0 is out of 3min. and the RA, DEC of the date are correct, the horizontal grid AZ is displaced, like was pointed out elsewhere.
After that date the forecasts degenerates increasly. Still here: rise/set times have precession injected, the current version not.

Author:  fenerit [ Sat, 19-07-14, 2:00 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

The post above was "cryptic" because topocentric. This is the same screenshot as geocentric. I can see it match! (aside the horiz. grid's issue).
Attachment:
jupiter_geocentric.png
jupiter_geocentric.png [ 156.53 KiB | Viewed 5137 times ]

Author:  fenerit [ Sun, 20-07-14, 21:24 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

John, the collation work. I made a new ANSI file named "celestia_venus.tf" (it should mean "text fixes"?) with inside the block of the changed values and a blank space at end. Then I've modified the SPICE Venus .SSC in the part of SpiceRotation:
Code:
SpiceRotation
{
   Kernel [ "pck00010.tpc" "naif0010.tls" "celestia_venus.tf" ]
   Frame "IAU_VENUS"
}


any suggestion on which names to give to such .tf files so that could be more rigorous?

Author:  fenerit [ Thu, 24-07-14, 17:51 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

Recapitulating, before the madness...

1) Venus VSOP87
Attachment:
VSOP87_venus.jpg
VSOP87_venus.jpg [ 108.42 KiB | Viewed 5097 times ]

2) Venus SPICE default (+ "earth_fixed.tf")
Attachment:
SPICE_default_venus.jpg
SPICE_default_venus.jpg [ 99.54 KiB | Viewed 5097 times ]

Bad grid orientation (W), degrees, and planetary surface.

3) Venus SPICE default (+ "earth_fixed.tf + "celestia_venus.tf")
Attachment:
SPICE_celestia_venus_tf.jpg
SPICE_celestia_venus_tf.jpg [ 102.36 KiB | Viewed 5097 times ]

good degrees and planetary surface, bad grid orientation (W).

There is not way to get the (E) grid. BUT:

4) Uranus VSOP87
Attachment:
VSOP87_uranus.jpg
VSOP87_uranus.jpg [ 74.91 KiB | Viewed 5097 times ]

5) Uranus SPICE default (+ "earth_fixed.tf")
Attachment:
SPICE_default_uranus.jpg
SPICE_default_uranus.jpg [ 83.84 KiB | Viewed 5097 times ]

good grid (E), bad surface and bad degrees

6) Uranus SPICE default (+ "earth_fixed.tf + "celestia_uranus.tf")
Attachment:
SPICE_celestia_uranus_tf.jpg
SPICE_celestia_uranus_tf.jpg [ 83.47 KiB | Viewed 5097 times ]

they matches in all. Nonetheless the "rotation matrix" of the two "celestia_xxx.tf" is the same! In this case the grid was (E) in VSOP87 and is remained (E) in both SPICE settings, while in Venus was (E) in VSOP87 and then is become (W) in both SPICE settings.

Author:  fenerit [ Thu, 24-07-14, 18:26 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

...continuing...

Pluto VSOP87
Attachment:
VSOP87_pluto.jpg
VSOP87_pluto.jpg [ 84.09 KiB | Viewed 5096 times ]

Pluto SPICE default (+ "earth_fixed.tf")
Attachment:
SPICE_default_pluto.jpg
SPICE_default_pluto.jpg [ 85 KiB | Viewed 5096 times ]

They matches but the Pluto's pole has been inverted (IAU 2009 + erratum) with respect to VSOP87 and therefore should be so:

3) Pluto SPICE default (+ "earth_fixed.tf + "celestia_pluto.tf")
Attachment:
SPICE_celestia_pluto_tf.jpg
SPICE_celestia_pluto_tf.jpg [ 94.03 KiB | Viewed 5096 times ]


the .tf to play with:
Attachment:
SPICE_celestia_tf.zip [1.98 KiB]
Downloaded 205 times


P.S.
The variation in light shader by both SPICE configurations are still a mistery.

Author:  fenerit [ Thu, 24-07-14, 18:37 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

The only guess about the different grid's behavior is that Venus is an inner planet and Uranus an outer planet... :rool:

Author:  fenerit [ Fri, 22-08-14, 13:51 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

But what a hel... :evil:

just adding the minus sign before the SpiceRotation's Kernel table and all works fine!

Code:
SpiceRotation
       {
         Kernel         -[ "pck00010.tpc" "naif0010.tls" ]
         Frame               "IAU_VENUS"
       }     

Author:  fenerit [ Fri, 22-08-14, 16:35 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

...

Venus
Code:
SpiceRotation
{
   Kernel -[ "pck00010.tpc"  "naif0010.tls" ]
   Frame  "IAU_VENUS"
}


Uranus
Code:
SpiceRotation
{
      Kernel -[ "pck00010.tpc"  "naif0010.tls" ]
      Frame  "IAU_URANUS"     
}


Triton
Code:
SpiceRotation
{
      Kernel [ "pck00010.tpc" "celestia_triton.tf" ]
      Frame  "IAU_TRITON"
}


Pluto
Code:
SpiceRotation
{
      Kernel [ "pck00010.tpc" "celestia_pluto.tf" ]
      Frame  "IAU_PLUTO"
}


Charon
Code:
SpiceRotation
{
      Kernel [ "pck00010.tpc" "celestia_charon.tf"]
      Frame  "IAU_CHARON"
}


Attachment:
triton_pluto_charon_tf.zip [1.44 KiB]
Downloaded 192 times

Author:  John Van Vliet [ Fri, 22-08-14, 22:39 GMT ]
Post subject:  Re: Issue with Celestia Spice... or ... ???

i have not had time to do a spice / non spice comparison

i do have the new add on and tonight should be doing a non spice celestia 1.7 test

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