imap_processing.spice.time.epoch_to_fractional_doy#
- imap_processing.spice.time.epoch_to_fractional_doy(epoch: int | Iterable[int]) float | ndarray#
Convert epoch in TTJ2000ns to floating point day-of-year.
Uses SPICE’s timout function to directly extract day of year and # codespell:ignore time components, avoiding intermediate datetime parsing.
- Parameters:
epoch (int or Iterable[int]) – Epoch in TTJ2000ns format (nanoseconds since J2000). Can be a single integer or an iterable of integers.
- Returns:
doy – Floating point day of year (1.0 = Jan 1 00:00:00). Returns a scalar when epoch is a single integer, or a NumPy array when epoch is an iterable.
- Return type:
References
https://naif.jpl.nasa.gov/pub/naif/toolkit_docs/C/cspice/timout_c.html