lsst.obs.base  20.0.0-63-g7191b3b+c777709640
camera_tests.py
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21 
22 import abc
23 import collections
24 import math
25 
26 import lsst.geom
27 from lsst.afw.cameraGeom import FOCAL_PLANE, FIELD_ANGLE
28 
29 __all__ = ["CameraTests"]
30 
31 
32 class CameraTests(metaclass=abc.ABCMeta):
33  """Tests that the butler returns a useable Camera.
34 
35  In the subclasses's setUp():
36  * Call setUp_camera() to fill in required parameters.
37  """
38 
39  def setUp_camera(self,
40  camera_name=None,
41  n_detectors=None,
42  first_detector_name=None,
43  plate_scale=None,
44  ):
45  """Set up the necessary variables for camera tests.
46 
47  Parameters
48  ----------
49 
50  camera_name : `str`
51  name of this camera
52  n_detectors : `int`
53  number of detectors in this camera
54  first_detector_name : `str`
55  name of the first detector in this camera
56  plate_scale : `lsst.geom.Angle`
57  plate scale at center of focal plane, as angle-on-sky/mm
58  """
59  fields = ['camera_name',
60  'n_detectors',
61  'first_detector_name',
62  'plate_scale',
63  ]
64  CameraData = collections.namedtuple("CameraData", fields)
65  self.camera_data = CameraData(camera_name=camera_name,
66  n_detectors=n_detectors,
67  first_detector_name=first_detector_name,
68  plate_scale=plate_scale,
69  )
70 
71  def test_iterable(self):
72  """Simplest camera test: can we get a Camera instance, and does
73  iterating return Detectors?"""
74  camera = self.butler.get('camera', immediate=True)
75  self.assertIsInstance(camera, lsst.afw.cameraGeom.Camera)
76  for detector in camera:
77  msg = "Failed for detector={}".format(detector)
78  self.assertIsInstance(detector, lsst.afw.cameraGeom.Detector, msg=msg)
79 
80  def test_camera_butler(self):
81  """Check that the butler returns the right type of camera."""
82  camera = self.butler.get('camera', immediate=True)
83  self.assertEqual(camera.getName(), self.camera_data.camera_name)
84  self.assertEqual(len(camera), self.camera_data.n_detectors)
85  self.assertEqual(next(iter(camera)).getName(), self.camera_data.first_detector_name)
86 
87  def test_plate_scale(self):
88  """Check the plate scale at center of focal plane
89 
90  Check plate_scale using the FOCAL_PLANE to FIELD_ANGLE transform
91  from the camera.
92  """
93  plate_scale = self.camera_data.plate_scale
94  self.assertIsNotNone(plate_scale)
95  camera = self.butler.get('camera', immediate=True)
96  focalPlaneToFieldAngle = camera.getTransformMap().getTransform(FOCAL_PLANE, FIELD_ANGLE)
97  focalPlaneRadiusMm = 0.001 # an offset small enough to be in the linear regime
98  for offsetAngleRad in (0.0, 0.65, 1.3): # direction of offset; a few arbitrary angles
99  cosAng = math.cos(offsetAngleRad)
100  sinAng = math.sin(offsetAngleRad)
101  fieldAngleRadians = focalPlaneToFieldAngle.applyForward(
102  lsst.geom.Point2D(cosAng * focalPlaneRadiusMm, sinAng * focalPlaneRadiusMm))
103  fieldAngleRadius = math.hypot(*fieldAngleRadians) * lsst.geom.radians
104  measuredScale1 = fieldAngleRadius / focalPlaneRadiusMm
105  self.assertAnglesAlmostEqual(measuredScale1, plate_scale)
106 
107  focalPlanePos = focalPlaneToFieldAngle.applyInverse(
108  lsst.geom.Point2D(fieldAngleRadius.asRadians() * cosAng,
109  fieldAngleRadius.asRadians() * sinAng))
110  focalPlaneRadiusMm2 = math.hypot(*focalPlanePos)
111  measureScale2 = fieldAngleRadius / focalPlaneRadiusMm2
112  self.assertAnglesAlmostEqual(measureScale2, plate_scale)
lsst.obs.base.camera_tests.CameraTests.camera_data
camera_data
Definition: camera_tests.py:60
lsst.obs.base.camera_tests.CameraTests
Definition: camera_tests.py:32
lsst.obs.base.camera_tests.CameraTests.test_iterable
def test_iterable(self)
Definition: camera_tests.py:71
lsst.obs.base.camera_tests.CameraTests.test_plate_scale
def test_plate_scale(self)
Definition: camera_tests.py:87
lsst.obs.base.camera_tests.CameraTests.setUp_camera
def setUp_camera(self, camera_name=None, n_detectors=None, first_detector_name=None, plate_scale=None)
Definition: camera_tests.py:39
lsst.obs.base.camera_tests.CameraTests.test_camera_butler
def test_camera_butler(self)
Definition: camera_tests.py:80