ULTRA l1b: update de event time calculation

[lacoak21]

Change Summary

closes #2525

Overview

Use only spin phase from the aux packet to calculate event times. The ULTRA team does not want a fall back to the universal spin table. This was discussed at the most recent ULTRA tagup. I investigated past logs and only 1- ~10 events are not covered by the aux table time range.

File changes

• imap_processing/quality_flags.py
  • add new flag
• imap_processing/ultra/l1b/de.py
  • make sure spins that are nan are converted to fillval
    -imap_processing/ultra/l1b/extendedspin.py
  • Invalid spins need to be handled very carefully! We dont want to actually use them in extendedspin.py calculations.
  • imap_processing/ultra/l1b/ultra_l1b_extended.py
    • update event time calculation to return nan for data outside of the aux dataset.

[Copilot]

Copilot review overview

🟡 Changes recommended

Missing auxiliary coverage can still cause incorrect timestamps or abort downstream processing.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1 · 2

Open (3)

• Handle empty spin numbers when no events have AUX coverage · New
• Validate AUX coverage for each selected event row · New
• Scope missing-AUX behavior to DE event lookup · New

What changed in this PR

Updates ULTRA L1B event timing to rely exclusively on auxiliary spin data.

Changes:

• Flags and fill-values events outside auxiliary coverage.
• Excludes invalid spins from Extended Spin calculations.
• Adds the AUXOUTLIER quality flag and tests.

File	Description
imap_processing/​ultra/​l1b/​ultra_l1b_extended.py	Removes universal-spin fallback and flags missing auxiliary timing.
imap_processing/​ultra/​l1b/​quality_flag_filters.py	Includes AUXOUTLIER in outlier filtering.
imap_processing/​ultra/​l1b/​extendedspin.py	Excludes fill-valued spins from binning.
imap_processing/​ultra/​l1b/​de.py	Applies timing flags and spin fill values.
imap_processing/​ultra/​constants.py	Defines the nominal spin period.
imap_processing/​tests/​ultra/​unit/​test_ultra_l1b_extended.py	Tests uncovered-event timing behavior.
imap_processing/​quality_flags.py	Defines the new auxiliary outlier flag.

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[Copilot]

Copilot review overview

🟡 Changes recommended

Shared spin lookup behavior and invalid-spin quality flags can still produce incorrect downstream processing.

Get a fresh assessment by requesting another Copilot review.

Review effort: Balanced
Findings: 1 · 1 · 1

Open (3)

• Handle uncovered rate timestamps in spin info callers · New
• Scope missing-AUX behavior to DE event lookup
• Remove unconditional debug output from dead-time calculation · New

Resolved since last review (2)

• Handle empty spin numbers when no events have AUX coverage
• Validate AUX coverage for each selected event row

Previously missed (1)

In code that hasn't changed since last review

Mark invalid spin numbers as AUXOUTLIER

imap_processing/​ultra/​l1b/​de.py:218

Missing or fill-valued spin numbers are converted to the output sentinel here without setting AUXOUTLIER. When an AUX row has valid timing fields but an invalid spinnumber, get_event_times() leaves quality_outliers clear. Extended Spin excludes the event by its fill-valued spin, but the culling summaries still treat it as valid and bin it by de_event_met. Set AUXOUTLIER for the same invalid-spin mask before writing the spin array.

[tmplummer]

This all looks reasonable to me.