Add simplified virtual cube readout mode to METIS

METIS/FPA_metis_lms_smpl_layout.dat

@@ -0,0 +1,21 @@
+# name : METIS LMS H2RG-18 FPA
+# author : Fabian Haberhauer
+# sources: NA
+# date_created : 2025-05-08
+# date_modified : 2025-05-08
+# x_cen_unit : mm
+# y_cen_unit : mm
+# z_cen_unit : um
+# x_size_unit : pix
+# y_size_unit : pix
+# z_size_unit : pix
+# pixel_size_unit : mm
+# angle_unit : deg
+# gain_unit : electron/adu
+# image_plane_id : 0
+#
+# changes:
+# - 2025-05-08 (FH) create file
+#
+id x_cen y_cen z_cen x_size y_size z_size pixel_size angle gain
+ 0     0     0     0    109    109   5600      0.018   0.0  1.0

METIS/METIS_DET_IFU_SMPL.yaml

@@ -0,0 +1,83 @@
+---
+### H2RG DETECTOR
+object: detector
+alias: DET
+name: metis_lms_detector_array
+description: Simplified IFU cube detector
+date_modified: 2025-05-08
+changes:
+  - 2025-05-08 (FH) create file as copy of METIS_DET_IFU.yaml
+  - 2025-05-16 (FH) update included effects
+
+properties:
+  image_plane_id: 0
+  temperature: -233
+  dit: "!OBS.dit"
+  ndit: "!OBS.ndit"
+  mindit: 1.3               # seconds, Roy van Boekel, pers. communication
+  full_well: !!float 1.E5   # electrons, E-TNT-MPIA-1004, v1-0
+  gain: 2
+  dark_current: 0.1         # [e-/s]
+  readout_noise: 70         # electrons, AI on RvB: check
+  layout:
+    file_name: "FPA_metis_lms_smpl_layout.dat"
+  qe_curve:
+    file_name: "QE_detector_H2RG_METIS.dat"
+  linearity:
+    file_name: "FPA_linearity_HxRG.dat"
+
+effects:
+  - name: detector_array_list
+    description: METIS LMS detector array list
+    class: DetectorList3D
+    kwargs:
+      filename: "!DET.layout.file_name"
+
+  - name: quantum_efficiency
+    description: Quantum efficiency curves for each detector
+    class: QuantumEfficiencyCurve
+    kwargs:
+      filename: "!DET.qe_curve.file_name"
+
+  - name: auto_exposure
+    description: automatic determination of DIT and NDIT
+    class: AutoExposure
+    include: True
+    kwargs:
+      fill_frac: "!OBS.auto_exposure.fill_frac"
+
+  - name: exposure_action
+    description: Summing up sky signal for all DITs and NDITs
+    class: SummedExposure
+
+  - name: dark_current
+    description: METIS LMS dark current
+    class: DarkCurrent
+    kwargs:
+      value: "!DET.dark_current"
+
+  - name: shot_noise
+    description: apply poisson shot noise to images
+    class: ShotNoise
+
+  - name: detector_linearity
+    description: Linearity characteristics of H2RG chips
+    class: LinearityCurve
+    include: False
+    kwargs:
+      filename: "!DET.linearity.file_name"
+
+  - name: readout_noise
+    description: Readout noise frames
+    class: BasicReadoutNoise
+    kwargs:
+      noise_std: "!DET.readout_noise"
+      n_channels: 32
+
+  - name: ad_conversion
+    description: Apply gain and convert electron count into integers
+    class: ADConversion
+    include: True
+    kwargs:
+      dtype: uint16
+      gain: "!DET.gain"

METIS/METIS_LMS_SMPL.yaml

@@ -0,0 +1,67 @@
+---
+### METIS LMS NOMINAL MODE
+object: instrument
+alias: INST
+name: METIS_LMS
+description: base configuration for METIS LMS
+date_modified: 2025-05-08
+changes:
+  - 2025-05-08 (FH) create file as copy of METIS_LMS.yaml
+  - 2025-05-16 (FH) remove unneeded effects, add flux binning effect
+
+properties:
+  pixel_scale: 0.0082          # arcsec / pixel
+  plate_scale: 0.455555555556  # arcsec / mm
+  fp2_platescale: 0.303        # arcsec / mm
+  slice_width: 0.0207          # arcsec / slice
+  decouple_detector_from_sky_headers: True  # needed for spectroscopy
+  flatten: False  # cube output
+
+effects:
+  - name: metis_lms_surfaces
+    description: list of extra mirrors needed for the SPEC LMS mode
+    class: SurfaceList
+    kwargs:
+      filename: LIST_METIS_mirrors_lms.dat
+
+  - name: lms_efficiency
+    description: grating efficiency of METIS LMS
+    class: MetisLMSEfficiency
+    kwargs:
+      filename: "!OBS.trace_file"
+      wavelen: "!OBS.wavelen"
+
+  - name: psf
+    description: field constant, wavelength dependent PSF for imaging mode
+    class: FieldConstantPSF
+    kwargs:
+      filename: "!OBS.psf_file"
+      wave_key: "WAVELENG"
+      bkg_width: -1
+
+  - name: lsf
+    description: line-spread function for spectroscopic domain
+    class: LineSpreadFunction
+    kwargs:
+      wavelen: "!OBS.wavelen"
+      fit_slope:      3.795e-06  # use to compute dlam_per_pix [um/pix] as
+      fit_intercept: -4.659e-07  #   a function of wavelength [um]
+      slice_width: "!INST.slice_width"
+      pixel_scale: "!INST.pixel_scale"
+      spec_binwidth: "!SIM.spectral.spectral_bin_width"
+
+  - name: flux_binning
+    description: turn per arcsec per um to ph per s
+    class: FluxBinning3D
+
+---
+### default simulation parameters needed for a METIS simulation
+object: simulation
+alias: SIM
+name: METIS_simulation_parameters
+description: RC simulation parameters which need to change for a METIS run
+
+properties:
+  spectral:
+    spectral_bin_width: 1E-5  # microns, defines fov wavelengths
+    spectral_resolution: 200000  # defines skycalc resolution

METIS/code/fit_ifu_dispersion.py

@@ -0,0 +1,46 @@
+"""Compute IFU mean dispersion as a function of central wavelength
+
+The LineSpreadFunction effect needs the dispersion dlam_per_pix on
+the LMS detector to determine the width of the LSF kernel to be
+applied to the cube in mode `lms_cube`. The script computes the mean
+dispersion as (lam_max - lam_min)/4220 for a number of wavelength settings,
+and then performs a linear regression of dlam_per_pix against wavelength.
+LineSpreadFunction() uses the slope and intercept to get a sufficient
+approximation to the dispersion without having to reference TRACE_LMS.fits
+or instantiate MetisLMSSpectralTraces itself.
+"""
+# Author: Oliver Czoske
+# Date:   2025-05-21
+
+import numpy as np
+from scipy.stats import linregress
+from matplotlib import pyplot as plt
+import scopesim as sim
+
+if __name__ == "__main__":
+    sim.link_irdb("../../")    # from METIS/code/
+
+    NPIX = 4220    # twice 2048 plus gap, from FPA_metis_lms_layout.dat
+    wavelens = np.linspace(2.677, 5.332, 100)   # um
+    dlam_per_pix = np.zeros_like(wavelens)
+
+    for i, lamc in enumerate(wavelens):
+        cmd = sim.UserCommands(use_instrument="METIS",
+                               set_modes=["lms"],
+                               properties={"!OBS.wavelen": lamc})
+        metis = sim.OpticalTrain(cmd)
+        splist = metis['lms_spectral_traces']
+        lam_min = splist.meta['wave_min']
+        lam_max = splist.meta['wave_max']
+
+        dlam_per_pix[i] = (lam_max - lam_min) / NPIX
+
+    linfit = linregress(wavelens, dlam_per_pix)
+    slope = linfit.slope
+    intercept = linfit.intercept
+    print("Slope:    ", slope, "# um/pix")
+    print("Intercept:", intercept, "# um")
+
+    plt.plot(wavelens, dlam_per_pix, 'o')
+    plt.plot(wavelens, intercept + slope * wavelens)
+    plt.show()

METIS/default.yaml

@@ -6,6 +6,7 @@ alias: OBS
 name: METIS_default_configuration
 description: default parameters needed for a METIS simulation
 status: development
+needs_scopesim: "v0.9"
 date_modified: 2024-09-04
 changes:
   - 2021-12-16 (OC) chopnod defaults to perpendicular
@@ -360,6 +361,28 @@ mode_yamls:
       adc: false
       detector_readout_mode: slow
 
+  - object: observation
+    alias: OBS
+    name: lms_cube
+    description: "METIS LM-band integral-field spectroscopy, nominal mode, cube output"
+    status: experimental
+    needs_scopesim: "v0.10.0a1"
+    yamls:
+      - Armazones.yaml
+      - ELT.yaml
+      - METIS.yaml
+      - METIS_LMS_SMPL.yaml
+      - METIS_DET_IFU_SMPL.yaml
+    properties:
+      ins_mode: LMS_cube          # use as FITS header keyword
+      psf_file: PSF_LM_9mag_06seeing.fits
+      interp_psf: False
+      slit: false
+      adc: false
+      trace_file: TRACE_LMS.fits
+      wavelen: 4.2
+      detector_readout_mode: slow
+
 ---
 ### default simulation parameters needed for a METIS simulation
 object: simulation