v0.2.4

[0.2.4] - 2024 - 7 - 15

Added

• Add J2 non-spherical terms for the gravitational models of Earth and Jupiter.
• Add non-gravitational force model for dust particles which includes the
  Poynting-Roberterson effect.
• Added Time.year_float which converts the Time object to the Year as a float.
• Added SimultaneousState.obs_vecs which creates vectors from the observer to the
  objects contained within the state.
• Added NEATM tutorial which gives an overview of NEATM along with a small example.

Changed

• Optimized SPICE kernel loading for Type 2 records, which is what DE440 is saved as.
  This means effectively all n-body propagation is now 15-20% faster than before.
• Removed SpiceKernel as a class, lowering all its methods to the submodule level,
  see #68 for more discussion.
• Removed Time object which was a wrapper over astropy.Time, instead making a
  custom implementation of time which is ~3-400x faster than previous.
• Improved orbital element conversion, leading to a 2-3x speedup in two body orbit
  propagation.
• Significant rewrite of the SPICE kernel file management, this rewrite is required
  so that future work can enable writing SPICE kernel files.
• Moved the downloading of Horizons spice kernels from SpiceKernel to horizons.
• Renamed all field of view checking functions to similar names: fov_static_check,
  fov_state_check, and fov_spice_check. These functions are exposed at the base
  level of neospy.
• Moved much of the python documentation into the rust wrappers, and removed the
  remaining empty python files. Part of the rewrite involved moving and renaming many
  functions.
• Updated nalgebra to minimum version ^0.33.0, which uses a simplified allocator.
• Fixed minimum versions for all rust libraries.

Fixed

• Orbital Elements now correctly computes true_anomaly, mean_anomaly,
  eccentric_anomaly, semi_major_axis, and mean_motion for parabolic and
  hyperbolic orbits.
• Two body propagation for parabolic orbits was incorrect.
• Typo in Observability example was leading to an incorrect Magnitude value.
• Astropy WCS warnings are now suppressed.
• SpiceKernels.moon_illuminated_frac now agrees with JPL Horizons, this was doing a
  geometric calculation which was correct, but with a different interpretation than
  desired.

Removed

• Removed support for SPK Files of type 3, these should be a trivial change from type 2
  however I do not have access to a file of type 3 for testing. Because it cannot be
  validated at the moment, the code has been removed.