def readpos(posfilepath):
    f = open(posfilepath, encoding='gb18030', errors='ignore')
    # ln = f.readline()
    # while ln:
    #     if '%  GPST' in ln:
    #         if 'latitude(deg)' in ln:
    #             posmode = 'llh'
    #         break
    #     ln = f.readline()
    llh = []
    while 1:
        ln = f.readline()
        if not ln:
            break
        # content = ln.split(' ')
        tow = float(ln[5:11])
        lat = float(ln[17:30])
        lon = float(ln[32:45])
        llh.append([tow,lat,lon])
    f.close()
    return llh