landsat_downloader.py 文件源码

 复制代码def next_overpass (date1, path, sat):
    """ provides the next overpass for path after date1
    """
    date0_L5 = datetime.datetime(1985,5,4)
    date0_L7 = datetime.datetime(1999,1,11)
    date0_L8 = datetime.datetime(2013,5,1)
    if sat == 'LT5':
        date0 = date0_L5
    elif sat == 'LE7':
        date0 = date0_L7
    elif sat == 'LC8':
        date0 = date0_L8
    next_day=math.fmod((date1-date0).days-cycle_day(path)+1,16)
    if next_day != 0:
        date_overpass = date1+datetime.timedelta(16-next_day)
    else:
        date_overpass = date1

    return date_overpass