def create_s1_product_specs(product_type='*', polarisation='*', beam='*'):
    """Convert Sentinel-1's product metadata to scihub's product attributes

    Default values for all product specifications is the wildcard
    '*' in order to check for all

    :param product_type: Sentinel-1 product type (RAW, SLC, GRD),
                         defaults to '*'
    :type product_type: str
    :param polarisation: Sentinel-1 polarisation mode (VV; VV VH; HH; HH HV),
                         defaults to '*'
    :type polarisation: string
    :param beam: Sentinel-1 beam mode (IW; SM, EW), defaults to '*'
    :type beam: str
    :return: Copernicus' scihub compliant product specifications query string
    :rtype: str
    """

    # bring product type, polarisation and beam to query format
    return (
        f'producttype:{product_type} AND '
        f'polarisationMode:{polarisation} AND '
        f'sensoroperationalmode:{beam}'
    )