def get_point2dem_opts(tr, tsrs):
    """
    prepares argument for ASP's point cloud gridding algorithm (point2dem) cmd
    Parameters
    ----------
    tr: float/int
        target resolution of output DEM
    tsrs: str
        projection of output DEM 
    
    Returns
    ----------
    point2dem_opts: list
        list of point2dem parameteres
    """

    point2dem_opts = []
    point2dem_opts.extend(['--tr', str(tr)])
    point2dem_opts.extend(['--t_srs', tsrs])
    point2dem_opts.extend(['--errorimage'])
    return point2dem_opts