calculateSipWcsHeader

lsst.afw.geom.calculateSipWcsHeader(wcs, order, bbox, spacing, header=None)

Generate a SIP WCS header approximating a given SkyWcs

Parameters:
wcslsst.afw.geom.SkyWcs

World Coordinate System to approximate as SIP.

orderint

SIP order (equal to the maximum sum of the polynomial exponents).

bboxlsst.geom.Box2I

Bounding box over which to approximate the wcs.

spacingfloat

Spacing between sample points.

headerlsst.daf.base.PropertyList, optional

Header to which to add SIP WCS keywords.

Returns:
headerlsst.daf.base.PropertyList

Header including SIP WCS keywords.

Examples

>>> header = calculateSipWcsHeader(exposure.getWcs(), 3, exposure.getBBox(), 20)
>>> sipWcs = SkyWcs(header)