webbpsf_ext.coords.ap_radec

webbpsf_ext.coords.ap_radec(ap_obs, ap_ref, coord_ref, pa, base_off=(0, 0), dith_off=(0, 0), get_cenpos=True, get_vert=False)[source]

Aperture reference point(s) RA/Dec

Given the (RA, Dec) and position angle of a given reference aperture, return the (RA, Dec) associated with the reference point (usually center) of a different aperture. Can also return the corner vertices of the aperture.

Typically, the reference aperture (ap_ref) is used for the telescope pointing information (e.g., NRCALL), but you may want to determine locations of the individual detector apertures (NRCA1_FULL, NRCB3_FULL, etc).

Parameters

  • ap_obs (str) – Name of observed aperture (e.g., NRCA5_FULL)

  • ap_ref (str) – Name of reference aperture (e.g., NRCALL_FULL)

  • coord_ref (tuple or list) – Center position of reference aperture (RA/Dec deg)

  • pa (float) – Position angle in degrees measured from North to V3 axis in North to East direction.

Keyword Arguments

  • base_off (list or tuple) – X/Y offset of overall aperture offset (see APT pointing file)

  • dither_off (list or tuple) – Additional offset from dithering (see APT pointing file)

  • get_cenpos (bool) – Return aperture reference location coordinates?

  • get_vert (bool) – Return closed polygon vertices (useful for plotting)?