projection¶
A collection of functions to support tangent-plane de-/projections.
- pysiaf.utils.projection.deproject_from_tangent_plane(x, y, ra_ref, dec_ref, scale=1.0, unwrap=True)[source]¶
Convert pixel coordinates into ra/dec coordinates using a tangent plane de-projection.
The projection’s reference point has to be specified. See the inverse transformation radec2Pix_TAN.
- Parameters:
- xfloat or array of floats
Pixel coordinate (default is in decimal degrees, but depends on value of scale parameter) x/scale has to be degrees.
- yfloat or array of floats
Pixel coordinate (default is in decimal degrees, but depends on value of scale parameter) x/scale has to be degrees.
- ra_reffloat
Right Ascension of reference point in decimal degrees
- dec_ref: float
declination of reference point in decimal degrees
- scalefloat
Multiplicative factor that is applied to the input values. Default is 1.0
- Returns:
- rafloat
Right Ascension in decimal degrees
- dec: float
declination in decimal degrees
- pysiaf.utils.projection.project_to_tangent_plane(ra, dec, ra_ref, dec_ref, scale=1.0)[source]¶
Convert ra/dec coordinates into pixel coordinates using a tangent plane projection.
Theprojection’s reference point has to be specified. Scale is a convenience parameter that defaults to 1.0, in which case the returned pixel coordinates are also in degree. Scale can be set to a pixel scale to return detector coordinates in pixels
- Parameters:
- rafloat
Right Ascension in decimal degrees
- dec: float
declination in decimal degrees
- ra_reffloat
Right Ascension of reference point in decimal degrees
- dec_ref: float
declination of reference point in decimal degrees
- scalefloat
Multiplicative factor that is applied to the returned values. Default is 1.0
- Returns:
- x,yfloat
pixel coordinates in decimal degrees if scale = 1.0