Add is_simulated and group_counter_*

* is_simulated has become necessary now that we are taking ComCam
  data in the lab that is pretending to be on sky.
* group_counter is needed to allow the new LSSTCam visit definitions
  to work. Headers now say they are N of M so the first and last
  values for observation_counter can be determined from a
  header.

python/astro_metadata_translator/properties.py

@@ -233,4 +233,14 @@ def simple_to_altaz(simple, **kwargs):
               "observation_counter": ("Counter of this observation. Can be counter within observing_day "
                                       " or a global counter. Likely to be observatory specific.",
                                       "int", int, None, None),
+              "is_simulated": ("Boolean indicating whether any part of this observation was simulated.",
+                               "bool", bool, None, None),
+              "group_counter_start": ("Observation counter for the start of the exposure group."
+                                      "Depending on the instrument the relevant group may be "
+                                      "visit_id or exposure_group.",
+                                      "int", int, None, None),
+              "group_counter_end": ("Observation counter for the end of the exposure group. "
+                                    "Depending on the instrument the relevant group may be "
+                                    "visit_id or exposure_group.",
+                                    "int", int, None, None),
               }

python/astro_metadata_translator/translator.py

@@ -946,6 +946,60 @@ def to_observation_counter(self):
         """
         return 0
 
+    @cache_translation
+    def to_group_counter_start(self) -> int:
+        """Return the observation counter of the observation that began
+        this group.
+
+        The definition of the relevant group is up to the metadata
+        translator. It can be the first observation in the exposure_group
+        or the first observation in the visit, but must be derivable
+        from the metadata of this observation.
+
+        Returns
+        -------
+        counter : `int`
+            The observation counter for the start of the relevant group.
+            Default implementation always returns the observation counter
+            of this observation.
+        """
+        return self.to_observation_counter()
+
+    @cache_translation
+    def to_group_counter_end(self) -> int:
+        """Return the observation counter of the observation that ends
+        this group.
+
+        The definition of the relevant group is up to the metadata
+        translator. It can be the last observation in the exposure_group
+        or the last observation in the visit, but must be derivable
+        from the metadata of this observation. It is of course possible
+        that the last observation in the group does not exist if a sequence
+        of observations was not completed.
+
+        Returns
+        -------
+        counter : `int`
+            The observation counter for the end of the relevant group.
+            Default implementation always returns the observation counter
+            of this observation.
+        """
+        return self.to_observation_counter()
+
+    @cache_translation
+    def to_is_simulated(self) -> bool:
+        """Return a boolean indicating whether any part of the observation
+        was simulated.
+
+        Returns
+        -------
+        is_simulated : `bool`
+            `True` if this exposure had simulated content. This can be
+            if some parts of the metadata or data were simulated. Default
+            implementation always returns `False`.
+        """
+        return False
+
     @classmethod
     def determine_translatable_headers(cls, filename, primary=None):
         """Given a file return all the headers usable for metadata translation.

tests/test_cfht.py

@@ -37,6 +37,9 @@ def test_megaprime_translator(self):
                            exposure_id=1038843,
                            exposure_group="1038843",
                            exposure_time=615.037*u.s,
+                           group_counter_end=1038843,
+                           group_counter_start=1038843,
+                           is_simulated=False,
                            object="w2.+2+2",
                            observation_counter=1038843,
                            observation_id="1038843",
@@ -64,6 +67,9 @@ def test_megaprime_translator(self):
                            exposure_id=849375,
                            exposure_group="849375",
                            exposure_time=300.202*u.s,
+                           group_counter_end=849375,
+                           group_counter_start=849375,
+                           is_simulated=False,
                            object="D3",
                            observation_counter=849375,
                            observation_id="849375",

tests/test_decam.py

@@ -36,6 +36,9 @@ def test_decam_translator(self):
                            exposure_id=229388,
                            exposure_group="229388",
                            exposure_time=200.0*u.s,
+                           group_counter_end=229388,
+                           group_counter_start=229388,
+                           is_simulated=False,
                            object="DES supernova hex SN-S1 tiling 22",
                            observation_counter=229388,
                            observation_id="ct4m20130901t060255",
@@ -64,6 +67,9 @@ def test_decam_translator(self):
                            exposure_id=160496,
                            exposure_group="160496",
                            exposure_time=0.0*u.s,
+                           group_counter_end=160496,
+                           group_counter_start=160496,
+                           is_simulated=False,
                            object="postflats-BIAS",
                            observation_counter=160496,
                            observation_id="ct4m20121211t220632",
@@ -92,6 +98,9 @@ def test_decam_translator(self):
                            exposure_id=412037,
                            exposure_group="412037",
                            exposure_time=86.0*u.s,
+                           group_counter_end=412037,
+                           group_counter_start=412037,
+                           is_simulated=False,
                            object="Blind15A_03",
                            observation_counter=412037,
                            observation_id="ct4m20150220t004721",
@@ -120,6 +129,9 @@ def test_decam_translator(self):
                            exposure_id=845291,
                            exposure_group="845291",
                            exposure_time=120.0*u.s,
+                           group_counter_end=845291,
+                           group_counter_start=845291,
+                           is_simulated=False,
                            object="",
                            observation_counter=845291,
                            observation_id="ct4m20190402t050618",

tests/test_sdss.py

@@ -36,6 +36,9 @@ def test_sdss_translator(self):
                            exposure_id=6377,
                            exposure_group="6377",
                            exposure_time=53.907456*u.s,
+                           group_counter_end=0,
+                           group_counter_start=0,
+                           is_simulated=False,
                            object="82 S",
                            observation_counter=0,
                            observation_id="6377 4 g 407",

tests/test_subaru.py

@@ -36,6 +36,9 @@ def test_hsc_translator(self):
                            exposure_id=904024,
                            exposure_group="904024",
                            exposure_time=30.0*u.s,
+                           group_counter_end=904024,
+                           group_counter_start=904024,
+                           is_simulated=False,
                            object="STRIPE82L",
                            observation_counter=904024,
                            observation_id="HSCA90402400",
@@ -62,6 +65,9 @@ def test_hsc_translator(self):
                            exposure_id=40900,
                            exposure_group="40900",
                            exposure_time=150.0*u.s,
+                           group_counter_end=40900,
+                           group_counter_start=40900,
+                           is_simulated=False,
                            object="SSP-Wide",
                            observation_counter=40900,
                            observation_id="HSCA04090000",
@@ -96,6 +102,9 @@ def test_suprimecam_translator(self):
                            exposure_id=53577,
                            exposure_group="53577",
                            exposure_time=200.0*u.s,
+                           group_counter_end=53577,
+                           group_counter_start=53577,
+                           is_simulated=False,
                            object="Ecliptic Deep Field",
                            observation_counter=53577,
                            observation_id="SUPE00535770",