def get_obs2coords(obs):
    """Create an observation to coordinate xwalk.

    Parameters
    ----------
    obs : tigernet.Observations

    Returns
    -------
    o2c : dict
        Observations to coordinates lookup.

    """

    o2c = {
        (ix, obs.df.loc[ix, obs.df_key]): (
            obs.df.loc[ix, obs.geo_col].x,
            obs.df.loc[ix, obs.geo_col].y,
        )
        for ix in obs.df.index
    }

    return o2c