spherical_pole_transform

sofia_redux.scan.coordinate_systems.coordinate_systems_numba_functions.spherical_pole_transform(x, px, cos_lat, sin_lat, p_cos_lat, p_sin_lat, phi0, reverse=False)

Transform spherical coordinates to a new pole.

The transformation occurs according to:

xt = arcsin((sin(py) * sin(y)) + (cos(py) * cos(y) * cos(dl)))
yt = o + arctan2((-sin(y) * cos(py)) + (cos(y) * sin(py) * cos(dl)),
                 (-cos(y) * sin(dl)))

For when reverse=False:

dl = x - px
o = pi/2 - phi0

and when reverse=True:

dl = x + phi0
o = x + pi/2

Here, (x, px) refer respectively to the coordinate and pole longitudes, while (y, py) refer to latitudes.

Parameters:

xnumpy.ndarray (float)

The coordinate LON values in radians of shape (1,) or (n,).

pxnumpy.ndarray (float)

The new pole longitude position in radians of shape (1,) or (n,).

cos_latnumpy.ndarray (float)

The cosine(latitude) values of shape (1,) or (n,).

sin_latnumpy.ndarray (float)

The sine(latitude) values of shape (1,) or (n,).

p_cos_latnumpy.ndarray (float)

The cosine(latitude) values of the pole of shape (1,) or (n,).

p_sin_latnumpy.ndarray (float)

The sine(latitude) values of the pole od shape (1,) or (n,).

phi0float

The phi0 angle in radians.

reversebool, optional

If True, perform the inverse transform (transform from pole rather than to).

Returns:

transformed_coordinatesnumpy.ndarray (float)

The transformed coordinates in radians of shape (2, n or 1).