computeAzAltFromBasePupil

lsst.cbp.coordUtils.computeAzAltFromBasePupil(vectorBase, vectorPupil)

Compute az/alt from a vector in the base frame and the same vector in the pupil frame.

Parameters:

vectorBase : iterable of three float

3-dimensional vector in the base frame.

vectorPupil : iterable of float

The same vector in the pupil frame. This vector should be within 45 degrees or so of the optical axis for accurate results.

Returns:

pupilAzAlt : lsst.geom.SpherePoint

Pointing of the pupil frame as internal azimuth, altitude.

Raises:

ValueError

If vectorPupil x <= 0

Notes

The magnitude of each vector is ignored, except that a reasonable magnitude is required in order to compute an accurate unit vector.