space::irbem::TotalFieldOpq
cheatah-space v0.1.0-alpha — Biome Standard 0.6.5-alpha
IGRF plus Olson & Pfitzer (1977), as a single field — the TotalFieldT89 shape without the activity level, because this model has none.
Satisfies GeoFieldModel, so it drops into trace_invariant, make_lstar and everything above them. The tilt fold is done ONCE, at construction, and the sine and cosine with it: a trace evaluates the field thousands of times per line, and refolding 172 coefficient pairs at each of them would cost more than the series itself.
Beyond 15 R_E the external part is the published zero, so a trace that leaves the model's region simply continues in the internal field — which is the published model's own behaviour and differs from IRBEM's wrapper, which refuses the whole field there. Inside the belts, where every drift shell this library traces lives, the two agree to the internal field's standard.
NMAX | the internal field's truncation degree. 10 reproduces IRBEM's own choice, which is what the differential tests run through; 13 is IGRF-14's full published degree. |
IrbemOpq.TotalFieldSuperposesInternalAndExternal IrbemOpq.LstarRunsThroughTheTotalFieldFunctions
internal | the internal field, already built for the epoch. |
rotations | the epoch's frame rotations — built once, reused for every point; their |
O(1) — one fold, sin, cos.
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalThe total field at a geographic point.
p | the position, GEO, Earth radii. |
B_internal + B_external, in GEO, nT. When the external model refuses the point — a non-finite input or a radius inside the Earth — the INTERNAL field is returned alone rather than a zero or a NaN; beyond 15 R_E the external part is the published zero and the sum is again the internal field. external_status says which.
One IGRF evaluation, one OP-77 evaluation, two 3x3 rotations.
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalWhether the external model answered at p without caveat, and if not, why.
p | the position, GEO, Earth radii. |
the external model's status; Status::Ok when it contributed in full.
One rotation and one envelope check.
none.
IrbemOpq.TotalFieldReportsWhenTheExternalModelDeclinesThe epoch's frame rotations — what any caller mapping frames needs.
the rotations this field was built with.
O(1).
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalThe internal part's Gauss coefficient g(n, m), in nT — the INTERNAL field's, for the same reason TotalFieldT89::g forwards: a superposition with a non-potential part has no expansion of its own, and every caller asking (the dipole moment, the trace step sizing) means the internal one.
n | the degree. |
m | the order. |
the internal part's coefficient.
O(1).
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalThe internal part's h(n, m), in nT — see g for why this forwards.
n | the degree. |
m | the order. |
the internal part's coefficient.
O(1).
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalThe internal field alone — what dipole_moment and any device staging need.
the internal model.
O(1).
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalThe folded external coefficients this field evaluates with — exposed so a differential harness can run the bare series through the same numbers the trace sees.
the parameter set folded at construction.
O(1).
none.
IrbemOpq.TotalFieldSuperposesInternalAndExternalConstants & variables
The internal part's truncation degree — what generic staging and buffer sizing read.