Merge pull request #451 from lsst/tickets/DM-38882

DM-38882: Update LSSTCam and TS8 physical filter names

python/lsst/obs/lsst/_instrument.py

@@ -31,6 +31,7 @@
 from .filters import (LSSTCAM_FILTER_DEFINITIONS, LATISS_FILTER_DEFINITIONS,
                       LSSTCAM_IMSIM_FILTER_DEFINITIONS, TS3_FILTER_DEFINITIONS,
                       TS8_FILTER_DEFINITIONS, COMCAM_FILTER_DEFINITIONS,
+                      GENERIC_FILTER_DEFINITIONS,
                       )
 
 from .translators import LatissTranslator, LsstCamTranslator, \
@@ -233,6 +234,7 @@ class LsstCamPhoSim(LsstCam):
     instrument = "LSSTCam-PhoSim"
     policyName = "phosim"
     translatorClass = LsstCamPhoSimTranslator
+    filterDefinitions = GENERIC_FILTER_DEFINITIONS
     visitSystem = VisitSystem.ONE_TO_ONE
 
     def getRawFormatter(self, dataId):
@@ -298,6 +300,7 @@ class LsstUCDCam(LsstCam):
     instrument = "LSST-UCDCam"
     policyName = "ucd"
     translatorClass = LsstUCDCamTranslator
+    filterDefinitions = GENERIC_FILTER_DEFINITIONS
     visitSystem = VisitSystem.ONE_TO_ONE
 
     def getRawFormatter(self, dataId):

python/lsst/obs/lsst/filters.py

@@ -45,14 +45,11 @@ def addFilter(filter_dict, band, physical_filter):
                                               )
 
 
-# The LSST Filters from L. Jones 05/14/2020
-#
-# N.b. DM-26623 requests that these physical names be updated once
-# the camera team has decided upon the final values (CAP-617)
+EmptyFilter = FilterDefinition(physical_filter="empty", band="white",
+                               alias={"no_filter", "open"})
 
-LsstCamFiltersBaseline = FilterDefinitionCollection(
-    FilterDefinition(physical_filter="empty", band="white",
-                     alias={"no_filter", "open"}),
+# Generic filters used by PhoSim and UCDCam
+LsstCamFiltersGeneric = FilterDefinitionCollection(
     FilterDefinition(physical_filter="u", band="u"),
     FilterDefinition(physical_filter="g", band="g"),
     FilterDefinition(physical_filter="r", band="r"),
@@ -61,6 +58,18 @@ def addFilter(filter_dict, band, physical_filter):
     FilterDefinition(physical_filter="y", band="y"),
 )
 
+# The LSST Filters from Tony Johnson, 05/09/2023, in DM-38882.
+LsstCamFiltersBaseline = FilterDefinitionCollection(
+    FilterDefinition(physical_filter="ph_5", band="white"),  # pinhole filter
+    FilterDefinition(physical_filter="ef_43", band="white"),  # "empty" filter
+    FilterDefinition(physical_filter="u_24", band="u"),
+    FilterDefinition(physical_filter="g_6", band="g"),
+    FilterDefinition(physical_filter="r_57", band="r"),
+    FilterDefinition(physical_filter="i_39", band="i"),
+    FilterDefinition(physical_filter="z_20", band="z"),
+    FilterDefinition(physical_filter="y_10", band="y"),
+)
+
 #
 # Define the filters present in the BOT.
 # According to Tony Johnson the possible physical filters are
@@ -131,6 +140,46 @@ def addFilter(filter_dict, band, physical_filter):
     for physical_filter, filter_defn in physical_filters.items():
         BOTFilters.append(FilterDefinition(**filter_defn))
 
+#
+# These are the filters used by the CCOB for both TS8 and LSSTCam.
+# For the testing of LSSTCam at SLAC, they will be combined with the
+# real LSSTCam filters, so we include those combinations in the CCOB
+# filter definitions.
+#
+CCOB_filter_map = {
+    "": "white",
+    "HIGH": "white",
+    "LOW": "white",
+    "uv": "u",
+    "blue": "g",
+    "red": "r",
+    "nm750": "i",
+    "nm850": "z",
+    "nm960": "y",
+}
+
+CCOBFilters = []
+for lsst_filter_def in (EmptyFilter, *LsstCamFiltersBaseline):
+    lsstcam_filter = lsst_filter_def.physical_filter
+    lsstcam_band = lsst_filter_def.band
+    for ccob_filter, ccob_band in CCOB_filter_map.items():
+        if lsstcam_band != "white" and ccob_band != "white" and band != ccob_band:
+            # Skip disallowed filter combinations based on band values.
+            continue
+        if ccob_filter == "":
+            # This would correspond to an entry already in
+            # LSSTCamFilterBaseline
+            continue
+        filters = lsstcam_filter, ccob_filter
+        physical_filter = FILTER_DELIMITER.join(filters).strip(FILTER_DELIMITER)
+        if lsstcam_band == "white":
+            band = ccob_band
+        else:
+            band = lsstcam_band
+        if physical_filter == "":
+            physical_filter = "empty"
+        CCOBFilters.append(FilterDefinition(band=band, physical_filter=physical_filter))
+
 #
 # The filters that we might see in the real LSSTCam (including in SLAC)
 #
@@ -139,8 +188,15 @@ def addFilter(filter_dict, band, physical_filter):
 # for all the BOT composite filters (i.e. "u~ND_OD1.0")
 #
 LSSTCAM_FILTER_DEFINITIONS = FilterDefinitionCollection(
+    EmptyFilter,
     *LsstCamFiltersBaseline,
     *BOTFilters,
+    *CCOBFilters,
+)
+
+GENERIC_FILTER_DEFINITIONS = FilterDefinitionCollection(
+    EmptyFilter,
+    *LsstCamFiltersGeneric,
 )
 
 #
@@ -152,7 +208,8 @@ def addFilter(filter_dict, band, physical_filter):
     FilterDefinition(physical_filter="550CutOn")]
 
 TS3_FILTER_DEFINITIONS = FilterDefinitionCollection(
-    *LsstCamFiltersBaseline,
+    EmptyFilter,
+    *LsstCamFiltersGeneric,
     *TS3Filters,
 )
 #
@@ -164,8 +221,11 @@ def addFilter(filter_dict, band, physical_filter):
     FilterDefinition(physical_filter="550CutOn")]
 
 TS8_FILTER_DEFINITIONS = FilterDefinitionCollection(
+    EmptyFilter,
+    *LsstCamFiltersGeneric,
     *LsstCamFiltersBaseline,
     *TS8Filters,
+    *CCOBFilters,
 )
 
 

python/lsst/obs/lsst/translators/lsst.py

@@ -662,6 +662,14 @@ def to_physical_filter(self):
         if not joined:
             joined = "unknown"
 
+        # Remove blank and "empty" fields.
+        joined = FILTER_DELIMITER.join(_ for _ in joined.split(FILTER_DELIMITER)
+                                       if _ and _ != "empty")
+
+        # Return "empty" if joined is blank at this point.
+        if not joined:
+            joined = "empty"
+
         return joined
 
     @cache_translation

python/lsst/obs/lsst/translators/lsstCam.py

@@ -15,10 +15,9 @@
 import logging
 import astropy.units as u
 
-from astro_metadata_translator import cache_translation
 from astro_metadata_translator.translators.helpers import is_non_science
 
-from .lsst import LsstBaseTranslator, SIMONYI_TELESCOPE, FILTER_DELIMITER
+from .lsst import LsstBaseTranslator, SIMONYI_TELESCOPE
 
 log = logging.getLogger(__name__)
 
@@ -138,28 +137,3 @@ def can_translate(cls, header, filename=None):
             if instrume == cls.supported_instrument.lower():
                 return True
         return False
-
-    @cache_translation
-    def to_physical_filter(self):
-        """Calculate the physical filter name.
-
-        Returns
-        -------
-        filter : `str`
-            Name of filter. Can be a combination of FILTER and FILTER2
-            headers joined by a "~" if FILTER2 is set and not empty.
-            Returns "UNKNOWN" if no filter is declared.
-        """
-        physical_filter = self._determine_primary_filter()
-
-        filter2 = None
-        if self.is_key_ok("FILTER2"):
-            self._used_these_cards("FILTER2")
-            filter2 = self._header["FILTER2"]
-            if self._is_filter_empty(filter2):
-                filter2 = None
-
-        if filter2:
-            physical_filter = f"{physical_filter}{FILTER_DELIMITER}{filter2}"
-
-        return physical_filter

python/lsst/obs/lsst/translators/ts8.py

@@ -188,7 +188,8 @@ def to_detector_serial(self):
     def to_physical_filter(self):
         """Return the filter name.
 
-        Uses the FILTPOS header.
+        Uses the FILTPOS header for older TS8 data.  Newer data can use
+        the base class implementation.
 
         Returns
         -------
@@ -197,19 +198,23 @@ def to_physical_filter(self):
 
         Notes
         -----
-        The calculations here are examples rather than being accurate.
-        They need to be fixed once the camera acquisition system does
-        this properly.
+        The FILTPOS handling is retained for backwards compatibility.
         """
 
         default = "unknown"
         try:
             filter_pos = self._header["FILTPOS"]
             self._used_these_cards("FILTPOS")
         except KeyError:
-            log.warning("%s: FILTPOS key not found in header (assuming %s)",
-                        self._log_prefix, default)
-            return default
+            # TS8 data from 2023-05-09 and later should be following
+            # DM-38882 conventions.
+            physical_filter = super().to_physical_filter()
+            # Some TS8 taken prior to 2023-05-09 have the string
+            # 'unspecified' as the FILTER keyword and don't really
+            # follow any established convention.
+            if 'unspecified' in physical_filter:
+                return default
+            return physical_filter
 
         try:
             return {