本菜鸟人：专业导航，善于寻北，精通惯导，兼职GPS，然近日因课题之需，方究机器之视觉也，乃叹人生之无常兮！惯导今天不讲，讲的话可以说上6天7夜（貌似被拍成电影了）。今天主题是GPS，GPS导航俗称：狗屁式导航（太TM俗了，老美怎么想出个这么个名字啊，God forgive me！）。

正题开始：
近日买了个GPS接受机跑了跑，甚喜。不知何时可用上本土的北斗啊。

第一日：石市天阴细雨，惊为江南之梅雨，连线开机，心如脱兔，目视终端（OK6410开发板，及配套的GPS模块），乱码！my God，Google之，然需波特率4800，改后接受正常。截取一段如下：

GPGGA,031531.391,,,,,0,00,,,M,0.0,M,,0000*58
$GPGSA,A,1,,,,,,,,,,,,,,,*1E    //<M = 手动，A = 自动>,<1 = 未定位， 2 = 二维定位， 3 = 三维定位>
$GPRMC,031531.391,V,,,,,,,030911,,,N*49
 // <UTC时间>,<A=有效定位，V=无效定位>   (既然无效的定位，后面的就不用看了)
$GPGGA,031532.403,,,,,0,00,,,M,0.0,M,,0000*57
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,031532.403,V,,,,,,,030911,,,N*46
$GPGGA,031533.392,,,,,0,00,,,M,0.0,M,,0000*59
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPRMC,031533.392,V,,,,,,,030911,,,N*48
$GPGGA,031534.392,,,,,0,00,,,M,0.0,M,,0000*5E // 隔几帧会送上一个长点的帧，包括了卫星的状态
$GPGSA,A,1,,,,,,,,,,,,,,,*1E
$GPGSV,3,1,12,25,84,328,,03,80,086,,06,65,062,,13,51,236,*7F
//<3表示有3个子帧>,<1表第一个子帧>,<12表可见卫星数>
//从第四个开始表示四组卫星(25,03,06,13)的情况
//<25表卫星号>,<84俯仰角>,<328方位角>,<信噪比（空字符表没有信号）>
$GPGSV,3,2,12,23,45,231,,07,19,046,,19,18,207,,31,16,125,*71
$GPGSV,3,3,12,14,15,179,,16,03,075,,21,01,031,,08,00,309,*70
$GPRMC,031534.392,V,,,,,,,030911,,,N*4F

结论由于天气原因，未能定位

次日：天清云淡

$GPGGA,012013.000,3800.5678,N,11400.1234,E,1,07,1.6,113.3,M,-15.0,M,,0000*7B
$GPGSA,A,3,03,06,19,16,20,32,31,,,,,,2.5,1.6,1.9*31
// 三维定位成功，收到信号的卫星为：03,06,19,16,20,32,31
$GPRMC,012013.000,A,3800.5678,N,11400.1234,E,0.12,349.87,040911,,,A*6F
$GPGGA,012014.000,3800.5678,N,11400.1234,E,1,07,1.6,113.2,M,-15.0,M,,0000*7E
$GPGSA,A,3,03,06,19,16,20,32,31,,,,,,2.5,1.6,1.9*31
$GPGSV,3,1,12,14,71,190,,16,67,267,35,07,51,082,,06,46,164,35*78
$GPGSV,3,2,12,23,46,303,,31,43,086,32,25,37,305,,03,36,184,37*78
$GPGSV,3,3,12,13,23,317,,32,15,225,33,20,14,249,33,19,06,190,32*73
$GPRMC,012014.000,A,3800.5678,N,11400.1234,E,0.13,343.31,040911,,,A*6D

成功定位，维度：3800.5678 (N)，经度：11400.1234 (E)