spiceypy.ckgp throws NotFoundError even though all kernels are loaded

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:

sc='-144'
datestr='2021-08-23T12:00:00'
tolerance=100
system='HGRTN'

et=spiceypy.spiceypy.str2et(datestr)
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.

[elastufka]

@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.

[mcostasitja]

@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: https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/req/ck.html 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 https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/pxform_c.html