Image sims: epoch-membership bounds for the trimmed 2048x4612 CCDs

astra.yaml

@@ -735,9 +735,15 @@ analyses:
           WCS inversion failure skips that CCD, lowering N_EPOCH, which caps
           how many exposures enter each galaxy's multi-epoch fit. This geometric
           count remains internal; the final catalogue's N_EPOCH counts only
-          epochs with a validated PSF.
+          epochs with a validated PSF. Image simulations' CCDs are trimmed to
+          2048x4612 with no overscan, so
+          their bounds are 0 < x < 2047, 0 < y < 4611 (input_types.image_sims
+          ccd_size, exported as SP_CCD_SIZE): under the data bounds an object
+          at 2048 < x < 2080 gains an epoch on pixels that do not exist, and
+          one at x < 33 loses a real one.
           Values:
-          SEXTRACTOR_RUNNER.CCD_SIZE = 33,2080,1,4612;
+          SEXTRACTOR_RUNNER.CCD_SIZE = ${SP_CCD_SIZE:-33,2080,1,4612};
+          input_types.image_sims.ccd_size = 0,2047,0,4611;
           SEXTRACTOR_RUNNER.MAKE_POST_PROCESS = True.
         default: trimmed_bounds_33_2080
         options:

example/cfis_image_sims/config_tile_Sx.ini

@@ -115,5 +115,6 @@ MAKE_POST_PROCESS = True
 # World coordinate keywords, SExtractor output. Format: KEY_X,KEY_Y
 WORLD_POSITION = XWIN_WORLD,YWIN_WORLD
 
-# Number of pixels in x,y of a CCD. Format: Nx,Ny
-CCD_SIZE = 33,2080,1,4612
+# Accepted CCD pixel bounds xmin,xmax,ymin,ymax (0-based, strict) of the
+# simulated 2048x4612 CCDs, which carry no overscan
+CCD_SIZE = 0,2047,0,4611

workflow/config.yaml

@@ -37,6 +37,12 @@ input_types:
     tile_detection: sextractor
     # @sc [decision:star_selection_psf.psf_modelling_software]
     psf_model: fake
+    # Epoch-membership CCD bounds (config_tile_Sx.ini CCD_SIZE, 0-based,
+    # strict): the simulated CCDs are 2048x4612 with no overscan, so a stamp
+    # centre rounds onto the image only for 0 < x < 2047, 0 < y < 4611. Data
+    # keeps the ini's MegaCam DATASEC default.
+    # @sc [decision:detection.epoch_membership_ccd_bounds]
+    ccd_size: 0,2047,0,4611
 
 # Entries per machine (SP_PROFILE, default nibi; implemented: nibi, candide)
 # and input_type. A run config may instead state `machine:`, which must

workflow/config/cfis/config_tile_Sx.ini

@@ -153,6 +153,9 @@ MAKE_POST_PROCESS = True
 # @sc [decision:preparation.object_position_columns]
 WORLD_POSITION = XWIN_WORLD,YWIN_WORLD
 
-# Accepted CCD pixel bounds xmin,xmax,ymin,ymax (0-based, strict)
+# Accepted CCD pixel bounds xmin,xmax,ymin,ymax (0-based, strict). The default
+# is the MegaCam DATASEC of an untrimmed 2112x4644 CCD; image simulations,
+# whose CCDs are trimmed to 2048x4612, set SP_CCD_SIZE (workflow config.yaml
+# input_types.image_sims.ccd_size).
 # @sc [decision:detection.epoch_membership_ccd_bounds]
-CCD_SIZE = 33,2080,1,4612
+CCD_SIZE = ${SP_CCD_SIZE:-33,2080,1,4612}

workflow/rules/tile.smk

@@ -528,13 +528,19 @@ if TILE_DETECTION == "unions_catalogue":
 
 
 def detect_env(tile):
-    """tile_detect's prologue exports: the catalogue to join, if any.
+    """tile_detect's prologue exports: the catalogue to join, if any, and for
+    image simulations the epoch-membership CCD bounds.
 
-    Empty under tile_detection: sextractor (image simulations), so that no
-    value left exported in the submitting shell reaches the job.
+    SP_MATCH_CATALOGUE is empty under tile_detection: sextractor (image
+    simulations), so that no value left exported in the submitting shell
+    reaches the job. SP_CCD_SIZE is exported only for image simulations (their
+    trimmed CCDs); data runs take config_tile_Sx.ini's default.
     """
     if TILE_DETECTION != "unions_catalogue":
-        return {"SP_MATCH_CATALOGUE": ""}
+        env = {"SP_MATCH_CATALOGUE": ""}
+        if INPUT_TYPE == "image_sims":
+            env["SP_CCD_SIZE"] = config["ccd_size"]
+        return env
     gic = f"{tile_dir(tile)}/output/run_sp_tile_Gic/get_images_runner/output"
     return {"SP_MATCH_CATALOGUE": f"{gic}/CFIS_cat{unit_num(tile)}.cat"}