LSSTApplications  18.1.0
LSSTDataManagementBasePackage
camera_tests.py
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1 #
2 # LSST Data Management System
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22 import abc
23 import collections
24 import math
25 
26 import lsst.afw.geom
27 from lsst.afw.cameraGeom import FOCAL_PLANE, FIELD_ANGLE
28 
29 __all__ = ["CameraTests"]
30 
31 
32 class CameraTests(metaclass=abc.ABCMeta):
33  """
34  Tests that the butler returns a useable Camera.
35 
36  In the subclasses's setUp():
37  * Call setUp_camera() to fill in required parameters.
38  """
39 
40  def setUp_camera(self,
41  camera_name=None,
42  n_detectors=None,
43  first_detector_name=None,
44  plate_scale=None,
45  ):
46  """
47  Set up the necessary variables for camera tests.
48 
49  Parameters
50  ----------
51 
52  camera_name : `str`
53  name of this camera
54  n_detectors : `int`
55  number of detectors in this camera
56  first_detector_name : `str`
57  name of the first detector in this camera
58  plate_scale : `lsst.afw.geom.Angle`
59  plate scale at center of focal plane, as angle-on-sky/mm
60  """
61  fields = ['camera_name',
62  'n_detectors',
63  'first_detector_name',
64  'plate_scale',
65  ]
66  CameraData = collections.namedtuple("CameraData", fields)
67  self.camera_data = CameraData(camera_name=camera_name,
68  n_detectors=n_detectors,
69  first_detector_name=first_detector_name,
70  plate_scale=plate_scale,
71  )
72 
73  def test_iterable(self):
74  """Simplest camera test: can we get a Camera instance, and does iterating return Detectors?"""
75  camera = self.butler.get('camera', immediate=True)
76  self.assertIsInstance(camera, lsst.afw.cameraGeom.Camera)
77  for detector in camera:
78  msg = "Failed for detector={}".format(detector)
79  self.assertIsInstance(detector, lsst.afw.cameraGeom.Detector, msg=msg)
80 
81  def test_camera_butler(self):
82  """Check that the butler returns the right type of camera."""
83  camera = self.butler.get('camera', immediate=True)
84  self.assertEqual(camera.getName(), self.camera_data.camera_name)
85  self.assertEqual(len(camera), self.camera_data.n_detectors)
86  self.assertEqual(next(iter(camera)).getName(), self.camera_data.first_detector_name)
87 
88  def test_plate_scale(self):
89  """Check the plate scale at center of focal plane
90 
91  Check plate_scale using the FOCAL_PLANE to FIELD_ANGLE transform
92  from the camera.
93  """
94  plate_scale = self.camera_data.plate_scale
95  self.assertIsNotNone(plate_scale)
96  camera = self.butler.get('camera', immediate=True)
97  focalPlaneToFieldAngle = camera.getTransformMap().getTransform(FOCAL_PLANE, FIELD_ANGLE)
98  focalPlaneRadiusMm = 0.001 # an offset small enough to be in the linear regime
99  for offsetAngleRad in (0.0, 0.65, 1.3): # direction of offset; a few arbitrary angles
100  cosAng = math.cos(offsetAngleRad)
101  sinAng = math.sin(offsetAngleRad)
102  fieldAngleRadians = focalPlaneToFieldAngle.applyForward(
103  lsst.afw.geom.Point2D(cosAng * focalPlaneRadiusMm, sinAng * focalPlaneRadiusMm))
104  fieldAngleRadius = math.hypot(*fieldAngleRadians) * lsst.afw.geom.radians
105  measuredScale1 = fieldAngleRadius / focalPlaneRadiusMm
106  self.assertAnglesAlmostEqual(measuredScale1, plate_scale)
107 
108  focalPlanePos = focalPlaneToFieldAngle.applyInverse(
109  lsst.afw.geom.Point2D(fieldAngleRadius.asRadians() * cosAng,
110  fieldAngleRadius.asRadians() * sinAng))
111  focalPlaneRadiusMm2 = math.hypot(*focalPlanePos)
112  measureScale2 = fieldAngleRadius / focalPlaneRadiusMm2
113  self.assertAnglesAlmostEqual(measureScale2, plate_scale)
def setUp_camera(self, camera_name=None, n_detectors=None, first_detector_name=None, plate_scale=None)
Definition: camera_tests.py:45
A collection of Detectors plus additional coordinate system support.
Definition: Camera.h:43
def format(config, name=None, writeSourceLine=True, prefix="", verbose=False)
Definition: history.py:168
Information about a CCD or other imaging detector.
Definition: Detector.h:62