Observational and orbit geometry parameters. Top: Example of the grid used by the IDL routine wispr_camera_coords to measure the projected angles in WISPR images. Respectively, the angle out of the plane is β and the elongation is γ. Bottom: Schematic of the geometry used taken from Liewer et al. (2019) where PSP’s orbit is approximated to be in the solar equatorial plane and through which we derived the geometrical equations (Eqs. ( A.3)- (A.4)).