calc_rotation_matrix

jwst.assign_wcs.util.calc_rotation_matrix(roll_ref: float, v3i_yang: float, vparity: int = 1) list[float][source]

Calculate the rotation matrix.

Parameters:
roll_reffloat

Telescope roll angle of V3 North over East at the ref. point in radians

v3i_yangfloat

The angle between ideal Y-axis and V3 in radians.

vparityint

The x-axis parity, usually taken from the JWST SIAF parameter VIdlParity. Value should be “1” or “-1”.

Returns:
matrixlist

The rotation matrix, [pc1_1, pc1_2, pc2_1, pc2_2]

Notes

The rotation is:

----------------
| pc1_1  pc2_1 |
| pc1_2  pc2_2 |
----------------