gwcs.wcstools.wcs_from_fiducial

gwcs.wcstools.wcs_from_fiducial(fiducial, coordinate_frame=None, projection=None, transform=None, name='', bounding_box=None, input_frame=None)

Create a WCS object from a fiducial point in a coordinate frame.

If an additional transform is supplied it is prepended to the projection.

Parameters:

  • fiducial (SkyCoord or tuple of float) –

    One of:

    A location on the sky in some standard coordinate system. A Quantity with spectral units. A list of the above.

  • coordinate_frame (CoordinateFrameProtocol) – The output coordinate frame. If fiducial is not an instance of SkyCoord, coordinate_frame is required.

  • projection (Projection) – Projection instance - required if there is a celestial component in the fiducial.

  • transform (Model (optional)) – An optional transform to be prepended to the transform constructed by the fiducial point. The number of outputs of this transform must equal the number of axes in the coordinate frame.

  • name (str) – Name of this WCS.

  • bounding_box (tuple) – The bounding box over which the WCS is valid. It is a tuple of tuples of size 2 where each tuple represents a range of (low, high) values. The bounding_box is in the order of the axes, axes_order. For two inputs and axes_order(0, 1) the bounding box is ((xlow, xhigh), (ylow, yhigh)).

  • input_frame (CoordinateFrameProtocol) – The input coordinate frame.