Implement persistence_step

- Implement persistence correction step
- Add persistence step to docs

Author: thomaswilliamsastro

CHANGES.rst

@@ -1,6 +1,7 @@
 1.3.1 (Unreleased)
 ==================
 
+- Implement ``persistence`` step, to correct for persistence in MIRI imaging
 - Fix backgrounds being wrongly moved in ``lv1_step``
 - Moved ``astrometric_align`` to a combined step, to avoid list ordering issues
 - Updated dependencies, added specific pins, dependabot, and CODEOWNERS

docs/reference_api.rst

@@ -138,6 +138,14 @@ Multi-Tile Destriping
     :members:
     :undoc-members:
 
+===========================
+MIRI Persistence Correction
+===========================
+
+.. autoclass:: pjpipe.PersistenceStep
+    :members:
+    :undoc-members:
+
 ============
 PSF Matching
 ============

docs/steps.rst

@@ -24,6 +24,7 @@ However, we highly recommend running these are part of the integrated pipeline.
     steps/lv1.rst
     steps/single_tile_destripe.rst
     steps/lv2.rst
+    steps/persistence.rst
     steps/get_wcs_adjust.rst
     steps/apply_wcs_adjust.rst
     steps/lyot_separate.rst

docs/steps/persistence.rst

@@ -0,0 +1,24 @@
+===============
+PersistenceStep
+===============
+
+As MIRI does not currently have a persistence correction step, we implement one
+based on `this paper <https://arxiv.org/pdf/2512.15477>`_. For each observation,
+we calculate a percentage flux correction (in detector pixel space) based on previous
+observations.
+
+This step also contains options to include a contribution from previous observation
+groups (rather than just the immediate dithers around the observation being considered),
+as well as from other bands.
+
+N.B. This step is currently undergoing testing, so a definitive recommendation on the settings
+is not currently available
+
+---
+API
+---
+
+.. autoclass:: pjpipe.PersistenceStep
+    :members:
+    :undoc-members:
+    :noindex:

pjpipe/__init__.py

@@ -28,6 +28,7 @@
                     ]
                     )
 
+from .anchoring import AnchoringStep
 from .apply_wcs_adjust import ApplyWCSAdjustStep
 from .astrometric_align import AstrometricAlignStep
 from .astrometric_catalog import AstrometricCatalogStep
@@ -46,11 +47,11 @@
 from .psf_model import PSFModelStep
 from .release import ReleaseStep
 from .regress_against_previous import RegressAgainstPreviousStep
+from .persistence import PersistenceStep
 from .pipeline import PJPipeline
+from .psf_matching import PSFMatchingStep
 from .single_tile_destripe import SingleTileDestripeStep
 from .utils import load_toml
-from .anchoring import AnchoringStep
-from .psf_matching import PSFMatchingStep
 
 __all__ = [
     "AnchoringStep",
@@ -69,6 +70,7 @@
     "MosaicIndividualFieldsStep",
     "MoveRawObsStep",
     "MultiTileDestripeStep",
+    "PersistenceStep",
     "PJPipeline",
     "PSFMatchingStep",
     "PSFModelStep",

pjpipe/persistence/__init__.py

@@ -0,0 +1,5 @@
+from .persistence_step import PersistenceStep
+
+__all__ = [
+    "PersistenceStep",
+]