分析从GPS接收的数据，航向角及方位角

[qiuhaitian]

分析从GPS接收的数据，最重要的是能从其中提取"航向角及方位角"的信息
$GPGSV,3,2,11,11,20,061,48,13,01,142,00,17,57,341,45,20,44,060,49*7F
$GPGSV,3,3,11,23,08,113,00,28,66,198,37,32,22,045,46,,,,*4F
$PGRME,14.9,M,14.0,M,20.5,M*10
$GPGLL,3130.129,N,12014.492,E,115345,A*2F
$PGRMZ,102,f,3*18
$PGRMM,WGS 84*06
$GPBOD,,T,,M,,*47
$GPRTE,1,1,c,0*07
$GPRMC,115346,A,3130.129,N,12014.492,E,000.0,182.3,080908,004.6,W*61
$GPRMB,A,,,,,,,,,,,,V*71
$GPGGA,115346,3130.129,N,12014.492,E,1,05,3.4,30.4,M,6.9,M,,*4E
$GPGSA,A,3,,04,,,11,,17,20,,,32,,4.5,3.4,1.0*34
及其航向角及方位角如何在坐标上表示

[qiuhaitian]

RMC中182.3为航向角，而方位角在RMB中 如$GPRMB,A,0.02,L,T002,T001,3134.402,N,12019.546,E,000.0,207.1,,V*12 其中207.1为方位角

[lazymorning]

我想知道航向角是怎么定义的，有什么用，能举个例子吗，万分感谢