# sigma_fov¶

mrspoc.sigma_fov(Gmag)[source] [edit on github]

Approximate Gaia astrometric uncertainty in a single measurement, i.e. “the along-scan accuracy per field of view crossing”, after Perryman et al. 2014, Eqn. 1 - 3.

Parameters: Gmag : float or ndarray Gaia G band magnitude. sigma : Quantity Approximate astrometric uncertainty for a target of magnitude Gmag, in units of arcseconds.