Correct one AU to 149597870700 m exactly #163
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1 AU per the IAU 2012 Resolution B2 and the BIPM published "The International System of Units (SI), 9th ed." Table 8 of "Non-SI units accepted for use with the SI units". Ref: https://www.iau.org/static/resolutions/IAU2012_English.pdf, accessed 2022-12-17 Ref: https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf, accessed 2022-12-17
As per the XXVIII General Assembly of the International Astronomical Union, (2012 Resolution B). And subsequent change by BIPM, the International Bureau of Weights and Measures, to the Non-SI units accepted for use with the SI units. Also, added some explicit official references to the value provided. (This commit here is effectively cherry-picked from what appeared to me to be the upstream libsgp4, see its merge request dnwrnr/sgp4#31).
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@esa would anyone actually care to take a look at this MR? In terms of unit conversions there is not really any more official source than "Bureau international des poids et mesures" (BIPM), i.e. the organisation behind the "International System of Units" (SI). We all know that @nasa does not always properly enforce SI units all the way with all subsystem providers (e.g. NASA's Mars Climate Orbiter), but ESA should at least follow SI standard or?? (I have reached out to NASA NAIF team regarding the SPICE kernels incorrect AU conversion, but they have not yet updated SPICE for this, and it is perhaps not the highest priority...). |
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We are using that number mainly for compatibility across tools, the user can change the value reassigning it. I am not sure we want to correct the value just now. Will keep this opened and monitor the cross compatibility situation ... |
Ok, thanks for the clarification. |
1 AU per the IAU 2012 Resolution B2 and the BIPM published "The International System of Units (SI), 9th ed."
Table 8 of "Non-SI units accepted for use with the SI units".
Ref: https://www.iau.org/static/resolutions/IAU2012_English.pdf, accessed 2022-12-17
Ref: https://www.bipm.org/documents/20126/41483022/SI-Brochure-9.pdf, accessed 2022-12-17
Please note, there is also the following lines from the NASA NAIF SPICE lib, but I leave without change here (@nasa should probably correct them upstream instead):
pykep/src/third_party/cspice/gfrfov_c.c
Line 581 in 6425e53
pykep/src/third_party/cspice/gffove.c
Line 1321 in 6425e53
pykep/src/third_party/cspice/gffove_c.c
Line 1180 in 6425e53