def _correct_grd_metadata_key(original_key: str) -> str:
    """
    Change an upper case GRD key to it's SLC metadata equivalent.
    By default this is uppercasing all keys; otherwise if the value in the
    `special_keys` dict will be used.

    Args:
        original_key: input metadata key
        special_keys: dictionary of special keys that require more than just lower case

    Return:
        corrected_key: corrected key name
    """

    special_keys = {
        "POSX": "posX",
        "POSY": "posY",
        "POSZ": "posZ",
        "VELX": "velX",
        "VELY": "velY",
        "VELZ": "velZ",
    }
    if original_key in special_keys:
        corrected_key = special_keys[original_key]

    else:
        corrected_key = original_key.lower()

    return corrected_key