ULTRA L1C HELIO index maps

[lacoak21]

Change Summary

Overview

Create ultra helio index maps on the fly to be used in the calculation of the exposure factor, efficiencies and geometric function. This is an alternative to reading in many ancillary files. It was decided that writing the code to do this is best incase we need to change it.

Most of the code to produce the index map was written by Claude after importing the Java code that nick uses. There were a few small issues to fix after this.

Updated Files

• imap_processing/ultra/constants.py
  • Add constants for helio index map creation
• imap_processing/ultra/l1b/lookup_utils.py
  • Fix inside fov function to match Nicks version (from java code)
• imap_processing/ultra/l1c/helio_pset.py
  • make index maps on the fly for helio psets.
    -imap_processing/ultra/l1c/l1c_lookup_utils.py
  • Fix valid pixel calculation to handle energy dependent index tables.
• imap_processing/ultra/l1c/make_helio_index_maps.py
  • code for calculating the helio index maps
• imap_processing/ultra/l1c/ultra_l1c_pset_bins.py
• fix code to use energy dependent index maps

Testing

• validation test for the index maps
• validation test for helio psets for efficiency and sensitivity values
• fixed other tests that were effected by the changes

[subagonsouth]

Just a few things worth reviewing.

[Copilot]

Pull request overview

This PR implements on-the-fly generation of heliocentric HEALPix index maps for ULTRA L1C processing as an alternative to reading multiple ancillary files. The implementation leverages SPICE kernels and includes necessary geometry transformations for heliocentric frame calculations.

Key Changes:

• New module make_helio_index_maps.py for generating index maps dynamically using SPICE
• Refactored helio pset calculations to use generated index maps instead of ancillary files
• Enhanced support for energy-dependent scattering rejection and index tables

Reviewed changes

Copilot reviewed 18 out of 23 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
make_helio_index_maps.py	New module implementing HEALPix index map generation with spacecraft velocity aberration and SPICE integration
helio_pset.py	Integrated on-the-fly index map generation, removed get_helio_adjusted_data call
l1c_lookup_utils.py	Enhanced to handle energy-dependent index tables, transposed array dimensions for consistency
ultra_l1c_pset_bins.py	Removed get_helio_adjusted_data function, fixed energy-dependent calculations, updated return type
constants.py	Added SPICE kernel paths and FOV constants for index map generation
pyproject.toml	Included sim_spice_kernels directory in package
SPICE kernels	Added simulation kernels (attitude, pointing, time, frames) for helio index map calculations

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[greglucas]

Do we need all of the sim_spice_kernels included in the released package because we want those sort of "frozen in time" in a sense? This means we wouldn't get any updated clock / instrument offset updates etc.

Looks good to me and I think you already discussed that with @subagonsouth so I'm fine with it all on the code front.

[lacoak21]

Do we need all of the sim_spice_kernels included in the released package because we want those sort of "frozen in time" in a sense? This means we wouldn't get any updated clock / instrument offset updates etc.

Looks good to me and I think you already discussed that with @subagonsouth so I'm fine with it all on the code front.

Yes exactly we want those never to change. Unless Nick requests they do.

[subagonsouth]

LGTM