The cbp package provides code for the LSST collimated beam projector (CBP). The primary objects of interest are:

lsst.cbp.CoordinateConverter: compute the telescope and CBP pointing that will give you a desired beam arrangement, such as placing beam b at point p on the pupil and point d on a specified detector.

lsst.cbp.computeHolePositions: compute hole positions for a CBP mask.

To construct an lsst.cbp.CoordinateConverter you will need to learn about configuration:

In order to configure and use an lsst.cbp.CoordinateConverter it may help to have some understanding of the coordinate systems involved:

Python API reference

lsst.cbp Package


computeHolePositions(detectorNames, ...)

Compute hole positions for a CBP mask.


BeamInfo(cameraGeom, name, holePos, ...)

Information about a beam at the telescope.

CoordinateConverter(config, maskInfo, cameraGeom)

Coordinate conversions for the collimated beam projector (CBP).

CoordinateConverterConfig(*, telPupilOffset, ...)

Configuration for the CoordinateConverter.

MaskInfo(name, defaultHole, holePositions[, ...])

Information about a CBP mask.

lsst.cbp.coordUtils Module


fieldAngleToVector(xyrad, flipX)

Convert a pupil field angle to a pupil unit vector.

vectorToFieldAngle(vec, flipX)

Convert a vector to a pupil field angle.

pupilPositionToVector(xyPos, flipX)

Convert a pupil plane position to a 3D vector.

computeShiftedPlanePos(planePos, fieldAngle, ...)

Compute the plane position of a vector on a plane shifted along the optical axis.

convertVectorFromBaseToPupil(vectorBase, ...)

Given a vector in base coordinates and the pupil pointing, compute the vector in pupil coordinates.

convertVectorFromPupilToBase(vectorPupil, ...)

Given a vector in pupil coordinates and the pupil pointing, compute the vector in base coords.

computeAzAltFromBasePupil(vectorBase, ...)

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

getFlippedPos(xyPos, flipX)

Get a 2-dimensional position with the x axis properly flipped.

rotate2d(pos, angle)

Rotate a 2-dimensional position by a given angle.

lsst.cbp.testUtils Module



An object containing a CoordinateConverter and the information used to create it.