Merge pull request #125 from desihub/binning

Simulate DESI spectra with the same output wavelength binning as the pipeline
desihub · Dec 4, 2024 · 0a15080 · 0a15080
2 parents 1765a63 + 07ed700
commit 0a15080
Show file tree

Hide file tree

Showing 5 changed files with 1,070 additions and 12 deletions.
diff --git a/docs/nb/SpecsimBinning.ipynb b/docs/nb/SpecsimBinning.ipynb
diff --git a/specsim/camera.py b/specsim/camera.py
@@ -87,8 +87,14 @@ def __init__(self, name, wavelength, throughput, row_size,
 
         # The arrays defining the CCD properties must all have identical
         # wavelength coverage.
+        # Since these arrays are generally interpolated, we might have some
+        # very small values due to roundoff errors. Set those to zero first.
+        for data in (self._row_size, self._fwhm_resolution, self._neff_spatial):
+            data[np.abs(data) < 1e-10] = 0.
+        # Use the row size array to define the CCD coverage.
         ccd_nonzero = np.where(self._row_size > 0)[0]
         ccd_start, ccd_stop = ccd_nonzero[0], ccd_nonzero[-1] + 1
+        # Verify that the other arrays have matching coverage.
         if (np.any(self._fwhm_resolution[:ccd_start] != 0) or
             np.any(self._fwhm_resolution[ccd_stop:] != 0)):
             raise RuntimeError('Resolution extends beyond CCD coverage.')

diff --git a/specsim/config.py b/specsim/config.py
@@ -226,7 +226,7 @@ def update(self):
         """
         # Initialize our wavelength grid.
         grid = self.wavelength_grid
-        nwave = 1 + int(math.floor(
+        nwave = 1 + int(np.round(
             (grid.max - grid.min) / grid.step))
         if nwave <= 0:
             raise ValueError('Invalid wavelength grid.')

diff --git a/specsim/data/config/desi.yaml b/specsim/data/config/desi.yaml
@@ -24,8 +24,8 @@ verbose: no
 #        CCD 3569.000 5949.000 5625.000 7741.000 7435.000 9834.000
 wavelength_grid:
     unit: Angstrom
-    min: 3550.0
-    max: 9850.0
+    min: 3550.05
+    max: 9850.05
     step: 0.1
 
 # The atmosphere configuration is interpreted and validated by the
@@ -203,10 +203,10 @@ instrument:
                 # Output pixels are used to report simulation results but are
                 # not the physical pixels.  The output pixel size must be a
                 # multiple of wavelength_grid.step.
-                output_pixel_size: 0.5 Angstrom
+                output_pixel_size: 0.8 Angstrom
             ccd:
                 table:
-                    path: specpsf/psf-quicksim.fits
+                    path: specpsf/psf-quicksim-rebin.fits
                     hdu: QUICKSIM-B
                     extrapolated_value: 0.0
                     columns:
@@ -222,7 +222,7 @@ instrument:
                         neff_spatial: { name: neff_spatial }
             throughput:
                 table:
-                    path: throughput/thru-b.fits
+                    path: throughput/thru-b_y1measured.fits
                     hdu: THROUGHPUT
                     extrapolated_value: 0.0
                     columns:
@@ -240,10 +240,10 @@ instrument:
                 # Output pixels are used to report simulation results but are
                 # not the physical pixels.  The output pixel size must be a
                 # multiple of wavelength_grid.step.
-                output_pixel_size: 0.5 Angstrom
+                output_pixel_size: 0.8 Angstrom
             ccd:
                 table:
-                    path: specpsf/psf-quicksim.fits
+                    path: specpsf/psf-quicksim-rebin.fits
                     hdu: QUICKSIM-R
                     extrapolated_value: 0.0
                     columns:
@@ -259,7 +259,7 @@ instrument:
                         neff_spatial: { name: neff_spatial }
             throughput:
                 table:
-                    path: throughput/thru-r.fits
+                    path: throughput/thru-r_y1measured.fits
                     hdu: THROUGHPUT
                     extrapolated_value: 0.0
                     columns:
@@ -277,10 +277,10 @@ instrument:
                 # Output pixels are used to report simulation results but are
                 # not the physical pixels.  The output pixel size must be a
                 # multiple of wavelength_grid.step.
-                output_pixel_size: 0.5 Angstrom
+                output_pixel_size: 0.8 Angstrom
             ccd:
                 table:
-                    path: specpsf/psf-quicksim.fits
+                    path: specpsf/psf-quicksim-rebin.fits
                     hdu: QUICKSIM-Z
                     extrapolated_value: 0.0
                     columns:
@@ -296,7 +296,7 @@ instrument:
                         neff_spatial: { name: neff_spatial }
             throughput:
                 table:
-                    path: throughput/thru-z.fits
+                    path: throughput/thru-z_y1measured.fits
                     hdu: THROUGHPUT
                     extrapolated_value: 0.0
                     columns: