class rubin_sim.maf.maf_contrib.FermatSpiralDitherFieldPerNightStacker(ra_col='fieldRA', dec_col='fieldDec', field_id_col='fieldID', night_col='night', num_points=60, max_dither=1.75, gold_angle=137.508)

Bases: FermatSpiralDitherFieldPerVisitStacker

Offset along a Fermat’s spiral with num_points, out to a maximum radius of max_dither. one dither offset per new night of observation of a field.

Note: dithers are confined to the hexagon inscribed in the circle with with radius max_dither Note: Fermat’s spiral is defined by r= c*sqrt(n), theta= n*angle, n= integer

ra_col: str

name of the RA column in the data. Default: ‘fieldRA’.


name of the Dec column in the data. Default: ‘fieldDec’.


name of the fieldID column in the data. Default: ‘fieldID’.


name of the night column in the data. Default: ‘night’.

num_points: int

number of points in the spiral. Default: 60

max_dither: float

radius of the maximum dither offset, in degrees. Default: 1.75

gold_angle: float

angle in degrees defining the spiral: theta= multiple of gold_angle. Default: 137.508