world2pix

sitelle.calibration.world2pix(star_list_deg, wcs, dxmap=None, dymap=None)

Conversion from physical coordinates to pixel coordinates using WCS and eventually dxdymaps. It’s the mathematical inverse of pix2world().

This supplements the astropy.wcs.WCS.all_world2pix by adding the possibility to use dxmaps and dymaps. For details see orb.utils.astrometry.world2pix(). The resulting pixel positions are then filtered using filter_star_list().

Parameters:

• star_list_deg (2D ndarray) – A 2D array containg RA/DEC positions of objects. The array should be column oriented ([[ra0, dec0], [ra1, dec1], [ra2, dec2], …])
• wcs (WCS) – The WCS transformation we want to use. See here for more details.
• dxmap (2D ndarray) – 2D array containing the astrometric third order correction on the x axis. If None (default value), the third order correction is not considered.
• dymap (2D ndarray) – 2D array containing the astrometric third order correction on the y axis. If None (default value), the third order correction is not considered.

Returns:

A 2D array of the same dimension than star_list_deg with pixel positions.

Return type:

ndarray