Variable lsst::afw::cameraGeom::TAN_PIXELS

Variable Documentation

CameraSysPrefix const lsst::afw::cameraGeom::TAN_PIXELS

Tangent-plane pixels on the detector (x, y unbinned pixels)

Converting from PIXELS to TAN_PIXELS has the effect of removing optical distortion (and the distortion due to rectangular pixels) with the point at the center of the detector being unaffected by the transformation.

In detail, PIXELS->TAN_PIXELS is PIXELS->FIELD_ANGLE plus an affine transformation, such that:

• The x,y axes are parallel to the detector axes

• The dimensions are nominal pixels at the center of the focal plane (where nominal pixels size is mean of x, y pixel size).

• The point at the center of the detector has the same value in PIXELS and TAN_PIXELS

This is a detector prefix; call Detector.makeCameraSys(TAN_PIXELS) to make a full CameraSys.