Public Member Functions
def	__init__ (self, wcsList, detectors, camera, n=100)

def	computeDistortionModel (self)

def	computePixelScale (self)

def	computeCameraPixelScale (self, detector_id=30)

Public Attributes
	wcsList

	camera

	detectors

	maxFocalRadius

	n

	fieldAngle

	radialScale

	tangentialScale

	fieldAngles

	radialScales

	tangentialScales

	fieldAngleStd

	radialScaleStd

	tangentialScaleStd

	log

Detailed Description

Convert a jointcal `~lsst.afw.geom.SkyWcs` into a distortion model and
detector positions (TODO) that can be used by `~lsst.afw.cameraGeom`.

Because this code only operates on the WCS, it is independent of the
format of the persisted output (e.g. gen2 separate files vs. gen3 bundled
visits).

Parameters
----------
wcsList : `list` [`lsst.afw.geom.SkyWcs`]
    The WCS to use to compute the distortion model from, preferably from
    multiple visits on the same tract.
detectors : `list` [`int`]
    Detector ids that correspond one-to-one with ``wcsList``.
camera : `lsst.afw.cameraGeom.Camera`
    The camera these WCS were fit for.
n : `int`
    Number of points to compute the pixel scale at, along the +y axis.

Definition at line 36 of file cameraGeometry.py.

Constructor & Destructor Documentation

◆ init()

def lsst.jointcal.cameraGeometry.CameraModel.__init__	(	self,
		wcsList,
		detectors,
		camera,
		n = `100`
	)

Definition at line 56 of file cameraGeometry.py.

     def __init__(self, wcsList, detectors, camera, n=100):
         self.wcsList = wcsList
         self.camera = camera
         self.detectors = detectors
         self.maxFocalRadius = self.camera.computeMaxFocalPlaneRadius()
         self.n = n
         # the computed radius and pixel scales
         self.fieldAngle = None  # degrees
         self.radialScale = None  # arcsec
         self.tangentialScale = None  # arcsec
         # the computed values for every input wcs
         self.fieldAngles = None
         self.radialScales = None
         self.tangentialScales = None
         self.fieldAngleStd = None
         self.radialScaleStd = None
         self.tangentialScaleStd = None
  
         self.log = _LOG.getChild("CameraModel")
  

Member Function Documentation

◆ computeCameraPixelScale()

def lsst.jointcal.cameraGeometry.CameraModel.computeCameraPixelScale	(	self,
		detector_id = `30`
	)

Compute the radial and tangential pixel scales using the distortion
model supplied with the camera.

This is designed to be directly comparable with the results of
`~CameraModel.computePixelScale`.

Parameters
----------
detector_id: `int`
    Detector identifier for the detector_id to use for the calculation.

Returns
-------
fieldAngle : `numpy.ndarray`
    Field angles in degrees.
radialScale : `numpy.ndarray`
    Radial direction pixel scales in arcseconds/pixel.
tangentialScale : `numpy.ndarray`
    Tangential direction pixel scales in arcseconds/pixel.

Definition at line 126 of file cameraGeometry.py.

     def computeCameraPixelScale(self, detector_id=30):
         """Compute the radial and tangential pixel scales using the distortion
         model supplied with the camera.
  
         This is designed to be directly comparable with the results of
         `~CameraModel.computePixelScale`.
  
         Parameters
         ----------
         detector_id: `int`
             Detector identifier for the detector_id to use for the calculation.
  
         Returns
         -------
         fieldAngle : `numpy.ndarray`
             Field angles in degrees.
         radialScale : `numpy.ndarray`
             Radial direction pixel scales in arcseconds/pixel.
         tangentialScale : `numpy.ndarray`
             Tangential direction pixel scales in arcseconds/pixel.
         """
         # Make a trivial SkyWcs to get a field angle->sky transform from.
         iwcToSkyWcs = lsst.afw.geom.makeSkyWcs(Point2D(0, 0), SpherePoint(0, 0, radians),
                                                lsst.afw.geom.makeCdMatrix(1.0 * radians, 0 * radians, True))
         iwcToSkyMap = iwcToSkyWcs.getFrameDict().getMapping("PIXELS", "SKY")
         skyFrame = iwcToSkyWcs.getFrameDict().getFrame("SKY")
  
         # Extract the transforms that are defined just on the camera.
         pixSys = self.camera[detector_id].makeCameraSys(cameraGeom.PIXELS)
         pixelsToFocal = self.camera.getTransform(pixSys, cameraGeom.FOCAL_PLANE)
         focalToField = self.camera.getTransform(cameraGeom.FOCAL_PLANE, cameraGeom.FIELD_ANGLE)
  
         # Build a SkyWcs that combines each of the above components.
         pixelFrame = ast.Frame(2, "Domain=PIXELS")
         focalFrame = ast.Frame(2, "Domain=FOCAL")
         iwcFrame = ast.Frame(2, "Domain=IWC")
         frameDict = ast.FrameDict(pixelFrame)
         frameDict.addFrame("PIXELS", pixelsToFocal.getMapping(), focalFrame)
         frameDict.addFrame("FOCAL", focalToField.getMapping(), iwcFrame)
         frameDict.addFrame("IWC", iwcToSkyMap, skyFrame)
         wcs = lsst.afw.geom.SkyWcs(frameDict)
  
         return self._computeDetectorPixelScale(detector_id, wcs)
  

◆ computeDistortionModel()

def lsst.jointcal.cameraGeometry.CameraModel.computeDistortionModel ( self )

Calculate the afw cameraGeom distortion model to be included in an
on-disk camera model.


PLACEHOLDER: This may be as simple as running `computePixelScale` and
then doing a numpy polynomial fit to it for the cameraGeom input.
However, we need to check details of how that distortion model is
stored in a Camera.
    e.g.: np.polyfit(self.fieldAngle, self.radialScale, poly_degree))

Definition at line 76 of file cameraGeometry.py.

     def computeDistortionModel(self):
         """Calculate the afw cameraGeom distortion model to be included in an
         on-disk camera model.
  
  
         PLACEHOLDER: This may be as simple as running `computePixelScale` and
         then doing a numpy polynomial fit to it for the cameraGeom input.
         However, we need to check details of how that distortion model is
         stored in a Camera.
             e.g.: np.polyfit(self.fieldAngle, self.radialScale, poly_degree))
         """
         raise NotImplementedError("not yet!")
  

◆ computePixelScale()

def lsst.jointcal.cameraGeometry.CameraModel.computePixelScale ( self )

Compute the radial and tangential pixel scale by averaging over
multiple jointcal WCS models.

Also computes the standard deviation and logs any WCS that are
significant outliers.
The calculations are stored in the ``fieldAngle[s]``,
``radialScale[s]``, and ``tangentialScale[s]`` member variables.

Definition at line 89 of file cameraGeometry.py.

     def computePixelScale(self):
         """Compute the radial and tangential pixel scale by averaging over
         multiple jointcal WCS models.
  
         Also computes the standard deviation and logs any WCS that are
         significant outliers.
         The calculations are stored in the ``fieldAngle[s]``,
         ``radialScale[s]``, and ``tangentialScale[s]`` member variables.
         """
         self.fieldAngles = []
         self.radialScales = []
         self.tangentialScales = []
         for id, wcs in zip(self.detectors, self.wcsList):
             fieldAngle, radial, tangential = self._computeDetectorPixelScale(id, wcs)
             self.fieldAngles.append(fieldAngle)
             self.radialScales.append(radial)
             self.tangentialScales.append(tangential)
         # TODO: For now, don't worry about small differences in the computed
         # field angles vs. their respective radial/tangential scales, just
         # assume all fieldAngle positions are "close enough" and warn if not.
         self.fieldAngle = np.mean(self.fieldAngles, axis=0)
         self.fieldAngleStd = np.std(self.fieldAngles, axis=0)
         if self.fieldAngleStd.max() > 1e-4:
             self.log.warning("Large stddev in computed field angles between visits (max: %s degree).",
                              self.fieldAngleStd.max())
         # import os; print(os.getpid()); import ipdb; ipdb.set_trace();
         self.radialScale = np.mean(self.radialScales, axis=0)
         self.radialScaleStd = np.std(self.radialScales, axis=0)
         if self.radialScaleStd.max() > 1e-4:
             self.log.warning("Large stddev in computed radial scales between visits (max: %s arcsec).",
                              self.radialScaleStd.max())
         self.tangentialScale = np.mean(self.tangentialScales, axis=0)
         self.tangentialScaleStd = np.std(self.tangentialScales, axis=0)
         if self.tangentialScaleStd.max() > 1e-4:
             self.log.warning("Large stddev in computed tangential scales between visits (max: %s arcsec).",
                              self.tangentialScaleStd.max())
  

Member Data Documentation

◆ camera

lsst.jointcal.cameraGeometry.CameraModel.camera

Definition at line 58 of file cameraGeometry.py.

◆ detectors

lsst.jointcal.cameraGeometry.CameraModel.detectors

Definition at line 59 of file cameraGeometry.py.

◆ fieldAngle

lsst.jointcal.cameraGeometry.CameraModel.fieldAngle

Definition at line 63 of file cameraGeometry.py.

◆ fieldAngles

lsst.jointcal.cameraGeometry.CameraModel.fieldAngles

Definition at line 67 of file cameraGeometry.py.

◆ fieldAngleStd

lsst.jointcal.cameraGeometry.CameraModel.fieldAngleStd

Definition at line 70 of file cameraGeometry.py.

◆ log

lsst.jointcal.cameraGeometry.CameraModel.log

Definition at line 74 of file cameraGeometry.py.

◆ maxFocalRadius

lsst.jointcal.cameraGeometry.CameraModel.maxFocalRadius

Definition at line 60 of file cameraGeometry.py.

◆ n

lsst.jointcal.cameraGeometry.CameraModel.n

Definition at line 61 of file cameraGeometry.py.

◆ radialScale

lsst.jointcal.cameraGeometry.CameraModel.radialScale

Definition at line 64 of file cameraGeometry.py.

◆ radialScales

lsst.jointcal.cameraGeometry.CameraModel.radialScales

Definition at line 68 of file cameraGeometry.py.

◆ radialScaleStd

lsst.jointcal.cameraGeometry.CameraModel.radialScaleStd

Definition at line 71 of file cameraGeometry.py.

◆ tangentialScale

lsst.jointcal.cameraGeometry.CameraModel.tangentialScale

Definition at line 65 of file cameraGeometry.py.

◆ tangentialScales

lsst.jointcal.cameraGeometry.CameraModel.tangentialScales

Definition at line 69 of file cameraGeometry.py.

◆ tangentialScaleStd

lsst.jointcal.cameraGeometry.CameraModel.tangentialScaleStd

Definition at line 72 of file cameraGeometry.py.

◆ wcsList

lsst.jointcal.cameraGeometry.CameraModel.wcsList

Definition at line 57 of file cameraGeometry.py.

The documentation for this class was generated from the following file:

/j/snowflake/release/lsstsw/stack/lsst-scipipe-0.7.0/Linux64/jointcal/22.0.1-25-g5bf6245+3ad8ecd50b/python/lsst/jointcal/cameraGeometry.py

Public Member Functions

Public Attributes