def _getSVlist(ln: str, N: int, sv: list) -> list:
    """ parse a line of text from RINEX2 SV list"""
    for i in range(N):
        s = ln[32+i*3:35+i*3].strip()
        if not s.strip():
            raise ValueError(f'did not get satellite names from {ln}')
        sv.append(s)

    return sv