NISP simulations (collimated beam)¶
Author: Yannick Copin y.copin@ipnl.in2p3.fr
We apply a naive spectrograph model (i.e. including a grism in a collimated beam) to the NISP instrument.
In [1]:
# Technical stuff related to the Jupyter notebook
%load_ext autoreload
%autoreload 2
%matplotlib inline
#import mpld3
#mpld3.enable_notebook()
import warnings
#warnings.filterwarnings("ignore")
In [2]:
import numpy as N
from matplotlib import pyplot as P
from spectrogrism import spectrogrism as S
from spectrogrism import nisp
from spectrogrism import distortion as D
Zemax simulations¶
Load the Zemax simulations:
In [3]:
datapath = "../spectrogrism/data/"
simulations = S.Configuration([
("name", "Zemax"),
(1, datapath + "run_190315.dat"), # 1st-order dispersed simulation
(0, datapath + "run_011115_conf2_o0.dat"), # 0th-order dispersed simulation
(2, datapath + "run_161115_conf2_o2.dat"), # 2nd-order dispersed simulation
('J', datapath + "run_071215_conf6_J.dat"), # J-band undispersed simulation
])
print(simulations)
----------------------- Configuration 'Zemax' ------------------------
name : Zemax
1 : ../spectrogrism/data/run_190315.dat
0 : ../spectrogrism/data/run_011115_conf2_o0.dat
2 : ../spectrogrism/data/run_161115_conf2_o2.dat
J : ../spectrogrism/data/run_071215_conf6_J.dat
In [4]:
zmx_pos = nisp.ZemaxPositions(simulations)
print(zmx_pos)
/data/ycopin/Softs/local/lib/python2.7/site-packages/spectrogrism-0.8-py2.7.egg/spectrogrism/nisp.py:186: UserWarning: Setting approximately null xindeg to 0
/data/ycopin/Softs/local/lib/python2.7/site-packages/spectrogrism-0.8-py2.7.egg/spectrogrism/nisp.py:190: UserWarning: Offsetting Yin by -0.85 deg
/data/ycopin/Softs/local/lib/python2.7/site-packages/spectrogrism-0.8-py2.7.egg/spectrogrism/nisp.py:194: UserWarning: Discarding wavelengths > 1.81 µm
Simulations 'Zemax': 4 modes
Order #1: ../spectrogrism/data/run_190315.dat
Order #0: ../spectrogrism/data/run_011115_conf2_o0.dat
Order #2: ../spectrogrism/data/run_161115_conf2_o2.dat
Band J: ../spectrogrism/data/run_071215_conf6_J.dat
Wavelengths: 13 steps from 1.20 to 1.80 µm
Coords: 289 sources
Plot input sources:
In [5]:
ax = zmx_pos.plot_input()
In [6]:
simcfg = zmx_pos.get_simcfg() # Simulation configuration
print(simcfg)
------------------ Simulation configuration 'Zemax' ------------------
name : Zemax
wave_npx : 13
wave_range : [1.1999999999999999e-06, 1.7999999999999999e-06]
modes : [1L, 0L, 2L, 'J']
input_coords : [[-0.00698132 -0.00698132]
[-0.00698132 -0.00610865]
[-0.00698132 -0.00523599]
...,
[ 0.00698132 0.00523599]
[ 0.00698132 0.00610865]
[ 0.00698132 0.00698132]]
Optical modeling¶
We use here the standard collimated model: telescope + collimator (CoLA) + [grism|filter] + camera (CaLA) + detector, even though the filter/grism is in a f/20 beam (while the CaLA produces a f/10 beam, hence the quoted magnification of 1/2).
In [7]:
# Optical modeling
optcfg = nisp.NISP_R # Optical configuration (default NISP)
print(optcfg)
------------------- Optical configuration 'NISP-R' -------------------
name : NISP-R
wave_ref : 1.5e-06
wave_range : [1.25e-06, 1.85e-06]
telescope_flength : 24.5
grism_dispersion : 9.8
grism_prism_material: FS
grism_grating_material: FS
grism_prism_angle : 0.0363028484415
grism_grating_rho : 13.1
grism_grating_blaze : 0.0453785605519
detector_pxsize : 1.8e-05
collimator_flength : 1.926
collimator_gdist_K1 : 0.474
collimator_gdist_y0 : 0.0232
grism_prism_tiltx : 0
grism_prism_tilty : 0
grism_prism_tiltz : 0
camera_flength : 0.9765
camera_gdist_K1 : -0.0317
camera_gdist_y0 : 0.201
detector_dx : 0.000499
detector_dy : 0.000634
In [8]:
spectro = S.Spectrograph(optcfg,
telescope=S.Telescope(optcfg))
print(spectro)
Reading 'collimator_gdist_K#i' parameters up to i=1
Reading 'camera_gdist_K#i' parameters up to i=1
---------------------------- Spectrograph ----------------------------
Telescope: f=24.5 m
Null geometric distortion
Null chromatic distortion
Collimator: f=1.9 m
Geometric distortion: center=(+0, +0.0232), K-coeffs=[ 0.474], P-coeffs=[]
Null chromatic distortion
Grism:
Prism [FS]: A=2.08°, tilts=+0',+0',+0'
Grating [FS]: rho=13.1 g/mm, blaze=2.60°
1st-order null-deviation wavelength: 1.24 µm
Camera: f=1.0 m
Geometric distortion: center=(+0, +0.201), K-coeffs=[-0.0317], P-coeffs=[]
Null chromatic distortion
Detector: pxsize=18 µm
Offset=(+0.499, +0.634) mm, angle=0.0 deg
Spectrograph magnification: 0.507
Central dispersion: 13.60 AA/px at 1.50 µm
In [9]:
print(" Spectrograph round-trip test ".center(70, '-'))
for mode in simcfg.get('modes', (1, 0, 2)):
if not spectro.test(simcfg.get_wavelengths(optcfg), mode=mode, verbose=False):
warnings.warn("Order #{}: backward modeling does not match.".format(mode))
else:
print("{}: OK".format(S.str_mode(mode)))
-------------------- Spectrograph round-trip test --------------------
Order #1: OK
Order #0: OK
Order #2: OK
Band J: OK
Imagery mode¶
Distortion model¶
In [10]:
xy = zmx_pos['J'].mean(axis=0).values # Mean (complex) positions (averaged over wavelengths) (289,)
grid = D.StructuredGrid(xy.reshape(17, 17))
print(grid)
Structured grid: 17 x 17 = 289 positions, y-x-
In [11]:
step, angle, offset, center = grid.estimate_parameters(fig=True)
print(u"Offset: ({0.real:.3f}, {0.imag:.3f}), step: {1:.3f}, angle: {2:.1f}°"
.format(offset, step, N.rad2deg(angle)))
print(u"Center of distortion: ({0.real:.3f}, {0.imag:.3f})".format(center))
Offset: (0.001, 0.000), step: 0.011, angle: 0.0°
Center of distortion: (-0.001, -0.012)
Optical model¶
In [12]:
result = spectro.adjust(zmx_pos, simcfg, tol=1e-4, modes=zmx_pos.bands,
optparams=['detector_dy', 'detector_dx',
'collimator_gdist_K1', 'camera_gdist_K1'])
====================== SPECTROGRAPH ADJUSTMENT =======================
Adjusted modes: ['J']
------------------------- Initial parameters -------------------------
detector_dy : 0.000634
detector_dx : 0.000499
collimator_gdist_K1 : 0.474
camera_gdist_K1 : -0.0317
Mode J RMS: 0.121303757397 mm = 6.73909763314 px
Total RMS: 0.121303757397 mm = 6.73909763314 px
Minimization succeeded: Converged (|f_n-f_(n-1)| ~= 0)
------------------------ Adjusted parameters -------------------------
detector_dy : 0.000637206962177
detector_dx : 0.000505160860991
collimator_gdist_K1 : 0.473999986675
camera_gdist_K1 : -0.0317002829108
RMS: 0.121104441223 mm = 6.72802451242 px
In [13]:
kwargs = dict(s=20, edgecolor='k', linewidths=1) # Outlined symbols
ax = zmx_pos.plot_output(modes=zmx_pos.bands, **kwargs)
phot_pos = spectro.predict_positions(simcfg)
kwargs = {} # Default
for band in zmx_pos.bands:
# Compute RMS on positions
rms = zmx_pos.compute_rms(phot_pos, mode=band)
print("Band {} RMS = {:.4f} mm = {:.2f} px".format(
band, rms / 1e-3, rms / spectro.detector.pxsize))
phot_pos.plot(ax=ax, zorder=0, # Draw below Zemax
modes=(band,),
label="{} {} (RMS={:.1f} px)".format(
phot_pos.name, band, rms / spectro.detector.pxsize),
**kwargs)
ax.axis([-100, +100, -100, +100]) # [mm]
ax.set_aspect('equal', adjustable='datalim')
ax.legend(fontsize='small', frameon=True, framealpha=0.5, title='')
ax.figure.set_size_inches(12, 10)
Band J RMS = 0.1211 mm = 6.73 px
Spectroscopy mode¶
In [14]:
spe_pos = spectro.predict_positions(simcfg, orders=zmx_pos.orders)
spe_pos.check_alignment(zmx_pos) # Would raise IndexError if incompatible
In [15]:
subsampling = 3 # Subsample output plot
kwargs = dict(s=20, edgecolor='k', linewidths=1) # Outlined symbols
ax = zmx_pos.plot_output(modes=zmx_pos.orders, subsampling=subsampling, **kwargs)
kwargs = {} # Default
for order in zmx_pos.orders:
# Compute RMS on spectra positions
rms = zmx_pos.compute_rms(spe_pos, mode=order)
print("Order #{} RMS = {:.4f} mm = {:.2f} px".format(order, rms / 1e-3, rms / spectro.detector.pxsize))
spe_pos.plot(ax=ax, zorder=0, # Draw below Zemax
modes=(order,),
subsampling=subsampling,
label="{} #{} (RMS={:.1f} px)".format(spe_pos.name, order, rms / spectro.detector.pxsize),
**kwargs)
ax.axis([-100, +100, -100, +100]) # [mm]
ax.set_aspect('equal', adjustable='datalim')
ax.legend(fontsize='small', frameon=True, framealpha=0.5, title='')
ax.figure.set_size_inches(12, 10)
Order #1 RMS = 0.3179 mm = 17.66 px
Order #0 RMS = 0.5342 mm = 29.68 px
Order #2 RMS = 0.2504 mm = 13.91 px
In [16]:
fig, axs = P.subplots(1, 3)
# Position offset quiver plots
for ax, order in zip(axs.ravel(), zmx_pos.orders):
zmx_pos.plot_offsets(spe_pos, ax=ax, mode=order)
ax.set_aspect('equal', adjustable='box')
ax.set_title("Order #{}".format(order))
fig.set_size_inches(12, 5)
