Include prism bandpasses in the roman module

galsim/roman/__init__.py

@@ -43,7 +43,11 @@
                        'H158': 0.04,
                        'F184': 0.17,
                        'K213': 4.52,
-                       'W146': 0.98}
+                       'W146': 0.98,
+                       'SNPrism': 0.00,
+                       'Grism_0thOrder': 0.00,
+                       'Grism_1stOrder': 0.00,
+                       }
 
 # Physical pixel size
 pixel_scale_mm = 0.01 # mm
@@ -64,8 +68,11 @@
 # Which bands should use the long vs short pupil plane files for the PSF.
 # F184, K213
 longwave_bands = ['F184', 'K213']
-# R062, Z087, Y106, J129, H158, W146
-shortwave_bands = ['R062', 'Z087', 'Y106', 'J129', 'H158', 'W146']
+# R062, Z087, Y106, J129, H158, W146, SNPrism, Grism_0thOrder, Grism_1stOrder.
+# Note that the last three are not imaging bands.
+non_imaging_bands = ['Grism_0thOrder', 'Grism_1stOrder', 'SNPrism']
+shortwave_bands = ['R062', 'Z087', 'Y106', 'J129', 'H158', 'W146'] \
+    + non_imaging_bands
 
 stray_light_fraction = 0.1
 

galsim/roman/roman_bandpass.py

@@ -29,7 +29,7 @@
 from ..errors import galsim_warn
 from .. import Bandpass, LookupTable
 
-def getBandpasses(AB_zeropoint=True, default_thin_trunc=True, **kwargs):
+def getBandpasses(AB_zeropoint=True, default_thin_trunc=True, include_all_bands=False, **kwargs):
     """Utility to get a dictionary containing the Roman ST bandpasses used for imaging.
 
     This routine reads in a file containing a list of wavelengths and throughput for all Roman
@@ -91,12 +91,17 @@ def getBandpasses(AB_zeropoint=True, default_thin_trunc=True, **kwargs):
                             use no thinning and truncation of bandpasses, or who want control over
                             the level of thinning and truncation, should have this be False.
                             [default: True]
+        include_all_bands:  Should the routine include the non-imaging bands (e.g., grisms)?
+                            This does not implement any dispersion physics by itself.
+                            There is currently no estimate for the thermal background for these
+                            bands and they are set to zero arbitrarily.
+                            [default: False]
         **kwargs:           Other kwargs are passed to either `Bandpass.thin` or
                             `Bandpass.truncate` as appropriate.
 
     @returns A dictionary containing bandpasses for all Roman imaging filters.
     """
-    from . import collecting_area
+    from . import collecting_area, non_imaging_bands
 
     # Begin by reading in the file containing the info.
     datafile = os.path.join(meta_data.share_dir, "roman", "Roman_effarea_20210614.txt")
@@ -134,8 +139,7 @@ def getBandpasses(AB_zeropoint=True, default_thin_trunc=True, **kwargs):
     bandpass_dict = {}
     # Loop over the bands.
     for index, bp_name in enumerate(data.dtype.names[1:]):
-        # Need to skip the prism and grism (not used for weak lensing imaging).
-        if bp_name=='SNPrism' or bp_name=='Grism_1stOrder' or bp_name=='Grism_0thOrder':
+        if include_all_bands is False and bp_name in non_imaging_bands:
             continue
 
         # Initialize the bandpass object.

tests/test_roman.py

@@ -488,6 +488,26 @@ def test_roman_bandpass():
     for key in nozp_bp:
         assert nozp_bp[key].zeropoint is None
 
+@timer
+def test_roman_nonimaging_bandpass():
+    """Test the Roman non-imaging bandpasses for basic sanity.
+    """
+    bp_imaging = galsim.roman.getBandpasses(AB_zeropoint=True)
+    bp_all = galsim.roman.getBandpasses(AB_zeropoint=True, include_all_bands=True)
+
+    # Check that the imaging bandpasses are in the all bandpasses
+    for key in bp_imaging:
+        assert key in bp_all
+
+    # Check that the non-imaging bandpasses are in the all bandpasses
+    assert 'Grism_0thOrder' in bp_all
+    assert 'Grism_1stOrder' in bp_all
+    assert 'SNPrism' in bp_all
+
+    # Check that the non-imaging bandpasses are not in the imaging bandpasses
+    assert 'Grism_0thOrder' not in bp_imaging
+    assert 'Grism_1stOrder' not in bp_imaging
+    assert 'SNPrism' not in bp_imaging
 
 @timer
 def test_roman_detectors():
@@ -783,7 +803,11 @@ def test_roman_basic_numbers():
                                'H158': 0.04,
                                'F184': 0.17,
                                'K213': 4.52,
-                               'W146': 0.98}
+                               'W146': 0.98,
+                               'SNPrism': 0.00,
+                               'Grism_0thOrder': 0.00,
+                               'Grism_1stOrder': 0.00,
+                              }
     ref_pupil_plane_file = os.path.join(
             galsim.meta_data.share_dir, 'roman', 'SCA2_rim_mask.fits.gz')
     ref_stray_light_fraction = 0.1