请问air800 接收gps原始数据输出脚后只有gps有数据，北斗的没有，原始数据如下：

$GNRMC,042917.000,A,3910.5951,N,11714.1484,E,0.280,190.72,280119,,,A*45

$GNVTG,190.72,T,,M,0.280,N,0.519,K,A*29

$GNGGA,042918.000,3910.5951,N,11714.1483,E,1,8,1.27,78.6,M,-2.7,M,,*66

$GPGSA,A,3,25,20,31,10,12,194,195,193,,,,,1.54,1.27,0.87*36

$BDGSA,A,3,,,,,,,,,,,,,1.54,1.27,0.87*18

$GPGSV,4,1,15,194,72,096,25,32,66,332,,25,58,111,32,10,57,190,32*4A

$GPGSV,4,2,15,193,50,159,32,14,49,310,,12,39,060,22,31,34,249,30*45

$GPGSV,4,3,15,20,29,172,33,18,12,285,,24,10,060,,195,09,151,32*43

$GPGSV,4,4,15,01,08,313,,22,06,321,,41,,,29*7D

$BDGSV,1,1,00*68

用PC软件接收后北斗的一直没有这个是怎么回事讷?