LSST Applications  21.0.0-172-gfb10e10a+18fedfabac,22.0.0+297cba6710,22.0.0+80564b0ff1,22.0.0+8d77f4f51a,22.0.0+a28f4c53b1,22.0.0+dcf3732eb2,22.0.1-1-g7d6de66+2a20fdde0d,22.0.1-1-g8e32f31+297cba6710,22.0.1-1-geca5380+7fa3b7d9b6,22.0.1-12-g44dc1dc+2a20fdde0d,22.0.1-15-g6a90155+515f58c32b,22.0.1-16-g9282f48+790f5f2caa,22.0.1-2-g92698f7+dcf3732eb2,22.0.1-2-ga9b0f51+7fa3b7d9b6,22.0.1-2-gd1925c9+bf4f0e694f,22.0.1-24-g1ad7a390+a9625a72a8,22.0.1-25-g5bf6245+3ad8ecd50b,22.0.1-25-gb120d7b+8b5510f75f,22.0.1-27-g97737f7+2a20fdde0d,22.0.1-32-gf62ce7b1+aa4237961e,22.0.1-4-g0b3f228+2a20fdde0d,22.0.1-4-g243d05b+871c1b8305,22.0.1-4-g3a563be+32dcf1063f,22.0.1-4-g44f2e3d+9e4ab0f4fa,22.0.1-42-gca6935d93+ba5e5ca3eb,22.0.1-5-g15c806e+85460ae5f3,22.0.1-5-g58711c4+611d128589,22.0.1-5-g75bb458+99c117b92f,22.0.1-6-g1c63a23+7fa3b7d9b6,22.0.1-6-g50866e6+84ff5a128b,22.0.1-6-g8d3140d+720564cf76,22.0.1-6-gd805d02+cc5644f571,22.0.1-8-ge5750ce+85460ae5f3,master-g6e05de7fdc+babf819c66,master-g99da0e417a+8d77f4f51a,w.2021.48
LSST Data Management Base Package
pupil.py
Go to the documentation of this file.
1 # This file is part of afw.
2 #
3 # Developed for the LSST Data Management System.
4 # This product includes software developed by the LSST Project
5 # (https://www.lsst.org).
6 # See the COPYRIGHT file at the top-level directory of this distribution
7 # for details of code ownership.
8 #
9 # This program is free software: you can redistribute it and/or modify
10 # it under the terms of the GNU General Public License as published by
11 # the Free Software Foundation, either version 3 of the License, or
12 # (at your option) any later version.
13 #
14 # This program is distributed in the hope that it will be useful,
15 # but WITHOUT ANY WARRANTY; without even the implied warranty of
16 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 # GNU General Public License for more details.
18 #
19 # You should have received a copy of the GNU General Public License
20 # along with this program. If not, see <https://www.gnu.org/licenses/>.
21 
22 __all__ = ['PupilFactory', 'Pupil']
23 
24 import numpy as np
25 
26 
27 class Pupil:
28  """Pupil obscuration function.
29 
30  Parameters
31  ----------
32  illuminated : `numpy.ndarray`, (Nx, Ny)
33  2D numpy array indicating which parts of the pupil plane are
34  illuminated.
35  size : `float`
36  Size of pupil plane array in meters. Note that this may be larger
37  than the actual diameter of the illuminated pupil to accommodate
38  zero-padding.
39  scale : `float`
40  Sampling interval of pupil plane array in meters.
41  """
42 
43  def __init__(self, illuminated, size, scale):
44  self.illuminatedilluminated = illuminated
45  self.sizesize = size
46  self.scalescale = scale
47 
48 
50  """Pupil obscuration function factory for use with Fourier optics.
51 
52  Parameters
53  ----------
54  visitInfo : `lsst.afw.image.VisitInfo`
55  Visit information for a particular exposure.
56  pupilSize : `float`
57  Size in meters of constructed Pupil array.
58  Note that this may be larger than the actual diameter of the
59  illuminated pupil to accommodate zero-padding.
60  npix : `int`
61  Constructed Pupils will be npix x npix.
62  """
63 
64  def __init__(self, visitInfo, pupilSize, npix):
65  self.visitInfovisitInfo = visitInfo
66  self.pupilSizepupilSize = pupilSize
67  self.npixnpix = npix
68  self.pupilScalepupilScale = pupilSize/npix
69  u = (np.arange(npix, dtype=np.float64) - (npix - 1)/2) * self.pupilScalepupilScale
70  self.u, self.vv = np.meshgrid(u, u)
71 
72  def getPupil(self, point):
73  """Calculate a Pupil at a given point in the focal plane.
74 
75  Parameters
76  ----------
77  point : `lsst.geom.Point2D`
78  The focal plane coordinates.
79 
80  Returns
81  -------
82  pupil : `Pupil`
83  The Pupil at ``point``.
84  """
85  raise NotImplementedError(
86  "PupilFactory not implemented for this camera")
87 
88  @staticmethod
89  def _pointLineDistance(p0, p1, p2):
90  """Compute the right-angle distance between the points given by `p0`
91  and the line that passes through `p1` and `p2`.
92 
93  Parameters
94  ----------
95  p0 : `tuple` of `numpy.ndarray`
96  2-tuple of numpy arrays (x, y focal plane coordinates)
97  p1 : ``pair`` of `float`
98  x,y focal plane coordinates
99  p2 : ``pair`` of `float`
100  x,y focal plane coordinates
101 
102  Returns
103  -------
104  distances : `numpy.ndarray`
105  Numpy array of distances; shape congruent to p0[0].
106  """
107  x0, y0 = p0
108  x1, y1 = p1
109  x2, y2 = p2
110  dy21 = y2 - y1
111  dx21 = x2 - x1
112  return np.abs(dy21*x0 - dx21*y0 + x2*y1 - y2*x1)/np.hypot(dy21, dx21)
113 
114  def _fullPupil(self):
115  """Make a fully-illuminated Pupil.
116 
117  Returns
118  -------
119  pupil : `Pupil`
120  The illuminated pupil.
121  """
122  illuminated = np.ones(self.u.shape, dtype=np.bool)
123  return Pupil(illuminated, self.pupilSizepupilSize, self.pupilScalepupilScale)
124 
125  def _cutCircleInterior(self, pupil, p0, r):
126  """Cut out the interior of a circular region from a Pupil.
127 
128  Parameters
129  ----------
130  pupil : `Pupil`
131  Pupil to modify in place.
132  p0 : `pair`` of `float`
133  2-tuple indicating region center.
134  r : `float`
135  Circular region radius.
136  """
137  r2 = (self.u - p0[0])**2 + (self.vv - p0[1])**2
138  pupil.illuminated[r2 < r**2] = False
139 
140  def _cutCircleExterior(self, pupil, p0, r):
141  """Cut out the exterior of a circular region from a Pupil.
142 
143  Parameters
144  ----------
145  pupil : `Pupil`
146  Pupil to modify in place
147  p0 : `pair`` of `float`
148  2-tuple indicating region center.
149  r : `float`
150  Circular region radius.
151  """
152  r2 = (self.u - p0[0])**2 + (self.vv - p0[1])**2
153  pupil.illuminated[r2 > r**2] = False
154 
155  def _cutRay(self, pupil, p0, angle, thickness):
156  """Cut out a ray from a Pupil.
157 
158  Parameters
159  ----------
160  pupil : `Pupil`
161  Pupil to modify in place.
162  p0 : `pair`` of `float`
163  2-tuple indicating ray starting point.
164  angle : `pair` of `float`
165  Ray angle measured CCW from +x.
166  thickness : `float`
167  Thickness of cutout.
168  """
169  angleRad = angle.asRadians()
170  # the 1 is arbitrary, just need something to define another point on
171  # the line
172  p1 = (p0[0] + 1, p0[1] + np.tan(angleRad))
173  d = PupilFactory._pointLineDistance((self.u, self.vv), p0, p1)
174  pupil.illuminated[(d < 0.5*thickness)
175  & ((self.u - p0[0])*np.cos(angleRad)
176  + (self.vv - p0[1])*np.sin(angleRad) >= 0)] = False
177 
178  def _centerPupil(self, pupil):
179  """Center the illuminated portion of the pupil in array.
180 
181  Parameters
182  ----------
183  pupil : `Pupil`
184  Pupil to modify in place
185  """
186  def center(arr, axis):
187  smash = np.sum(arr, axis=axis)
188  w = np.where(smash)[0]
189  return int(0.5*(np.min(w)+np.max(w)))
190  ycenter = center(pupil.illuminated, 0)
191  xcenter = center(pupil.illuminated, 1)
192  ytarget = pupil.illuminated.shape[0]//2
193  xtarget = pupil.illuminated.shape[1]//2
194  pupil.illuminated = np.roll(np.roll(pupil.illuminated,
195  xtarget-xcenter,
196  axis=0),
197  ytarget-ycenter,
198  axis=1)
def __init__(self, visitInfo, pupilSize, npix)
Definition: pupil.py:64
def __init__(self, illuminated, size, scale)
Definition: pupil.py:43