lsst.afw
20.0.0-9-g61a2a9a3d+14f89e4eca
|
Functions | |
def | getSipMatrixFromMetadata (metadata, name) |
def | makeDistortedTanWcs (tanWcs, pixelToFocalPlane, focalPlaneToFieldAngle) |
def | computePixelToDistortedPixel (pixelToFocalPlane, focalPlaneToFieldAngle) |
def lsst.afw.geom.wcsUtils.wcsUtilsContinued.computePixelToDistortedPixel | ( | pixelToFocalPlane, | |
focalPlaneToFieldAngle | |||
) |
Compute the transform ``pixelToDistortedPixel``, which applies optical distortion specified by ``focalPlaneToFieldAngle``. The resulting transform is designed to be used to convert a pure TAN WCS to a WCS that includes a model for optical distortion. In detail, the initial WCS will contain these frames and transforms:: PIXELS frame -> pixelToIwc -> IWC frame -> gridToIwc -> SkyFrame To produce the WCS with distortion, replace ``pixelToIwc`` with:: pixelToDistortedPixel -> pixelToIwc Parameters ---------- pixelToFocalPlane : `lsst.afw.geom.TransformPoint2ToPoint2` Transform parent pixel coordinates to focal plane coordinates focalPlaneToFieldAngle : `lsst.afw.geom.TransformPoint2ToPoint2` Transform focal plane coordinates to field angle coordinates Returns ------- pixelToDistortedPixel : `lsst.afw.geom.TransformPoint2ToPoint2` A transform that applies the effect of the optical distortion model.
Definition at line 157 of file wcsUtilsContinued.py.
def lsst.afw.geom.wcsUtils.wcsUtilsContinued.getSipMatrixFromMetadata | ( | metadata, | |
name | |||
) |
Extract a SIP matrix from FITS TAN-SIP WCS metadata. Omitted coefficients are set to 0 and all coefficients may be omitted. Parameters ---------- metadata : `lsst.daf.base.PropertySet` FITS metadata. name : `str` Name of TAN-SIP matrix (``"A"``, ``"B"``, ``"Ap"``, or ``"Bp"``). Returns ------- `numpy.array` The SIP matrix. Raises ------ TypeError If the order keyword ``<name>_ORDER`` (e.g. ``AP_ORDER``) is not found, the value of the order keyword cannot be read as an integer, the value of the order keyword is negative, or if a matrix parameter (e.g. ``AP_5_0``) cannot be read as a float.
Definition at line 33 of file wcsUtilsContinued.py.
def lsst.afw.geom.wcsUtils.wcsUtilsContinued.makeDistortedTanWcs | ( | tanWcs, | |
pixelToFocalPlane, | |||
focalPlaneToFieldAngle | |||
) |
Compute a WCS that includes a model of optical distortion. This is useful in the common case that the initial WCS entirely ignores the effect of optical distortion. Parameters ---------- tanWcs : `lsst.afw.geom.SkyWcs` A pure TAN WCS, such as is usually provided in raw data. This should have no existing compensation for optical distortion (though it may include an ``ACTUAL_PIXELS`` frame to model pixel-level distortions). pixelToFocalPlane : `lsst.afw.geom.TransformPoint2ToPoint2` Transform parent pixel coordinates to focal plane coordinates. This models the location of the CCD on the focal plane and is almost always an affine transformation. This can be obtained from the detector of an exposure. focalPlaneToFieldAngle : `lsst.afw.geom.TransformPoint2ToPoint2` Transform focal plane coordinates to field angle coordinates. This is a model for optical distortion, and is often a radial polynomial. This can be obtained from the camera geometry. Returns ------- lsst.afw.geom.SkyWcs A copy of `tanWcs` that includes the effect of optical distortion. Raises ------ RuntimeError If the current frame of `wcs` is not a SkyFrame; LookupError If 2-dimensional Frames with Domain "PIXELS" and "IWC" are not all found.
Definition at line 66 of file wcsUtilsContinued.py.