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spiceypy.ckgp throws NotFoundError even though all kernels are loaded

See original GitHub issue

Hi, I’m getting a NotFoundError that I can’t figure out. From what I understand of the C documentation, if the ck/ files are all loaded for a given date, the attitude data should be able to be found. Yet spiceypy.ckgp is not able to find anything.

Here’s the code:


sclkdp=spiceypy.spiceypy.sce2c(int(sc), et) #Ephemeris time, seconds past J2000.
cmat=spiceypy.spiceypy.ckgp(int(sc), sclkdp, tolerance, system)

I’ve checked both that the kernel files are present and that they are listed in the file that loads the kernels. Is there something I’m missing?

Anyway, thanks for any advice and for writing this package, 99% of the time it makes my life easier.

Issue Analytics

  • State:closed
  • Created 2 years ago
  • Comments:6 (3 by maintainers)

github_iconTop GitHub Comments

elastufkacommented, Nov 11, 2021

@marcsit Thanks, it works! I didn’t know the spacecraft frame had a different ID, since I was translating sswidl’s get_sunspice_roll and I must have missed the ID change in get_sunspice_cmat somehow.

mcostasitjacommented, Nov 11, 2021

@elastufka by the way, you should re-consider the value that you use for `tolerance’ I suggest that you take a look at the CK Required reading: and/or take a look at the ckgp_c function header.

In addition please note that this routine might not be the best to use for the purpose of obtaining an orientation matrix, instead I would suggest you to use: pxform_c

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