【IT168 技术文档】在Android平台上开发可能没有真机的时候，我们通过DDMS中载入KML或NMEA文件来模拟生产数据，使用方法参考新版ADT插件让Android开发更人性化一文，最终这两个文件加载到/data/misc/location/gps/nmea或/data/misc/location/gps/kml/

一、KML文件其实是一个XML文件，我们看下KML文件结构

1065 Brea Mall, Brea, CA 92821.kml

normal

#default_copy0+icon=http://maps.google.com/mapfiles/kml/pal3/icon60.png

highlight

#default_copy0+icon=http://maps.google.com/mapfiles/kml/pal3/icon52.png

1.1

http://maps.google.com/mapfiles/kml/pal3/icon52.png

1.1

http://maps.google.com/mapfiles/kml/pal3/icon60.png

1065 Brea Mall, Brea, CA 92821

1065 Brea Mall, Brea, CA 92821

-117.883593

33.916991

0

1000

0

0

#default_copy0+nicon=http://maps.google.com/mapfiles/kml/pal3/icon60.png+hicon=http://maps.google.com/mapfiles/kml/pal3/icon52.png

-117.883593,33.916991,0

二、NMEA协议就是常规的GPS数据，通过串口直接获取到的，如下

$GPRMC,003347.000,A,3725.3433,N,12205.7920,W,0.08,149.46,061007,,,D*70

$GPRMC,003348.000,A,3725.3433,N,12205.7921,W,0.05,142.51,061007,,,D*7E

$GPRMC,003349.000,A,3725.3432,N,12205.7921,W,0.08,159.56,061007,,,D*7E

$GPRMC,003350.000,A,3725.3432,N,12205.7921,W,0.06,151.59,061007,,,D*7F

$GPRMC,003351.000,A,3725.3432,N,12205.7921,W,0.20,120.57,061007,,,D*72

实例:

解析方法:

RMC = Recommended Minimum Specific GPS/TRANSIT Data

$GPRMC,hhmmss.ss,A,llll.ll,a,yyyyy.yy,a,x.x,x.x,ddmmyy,x.x,a*hh

1 = UTC(universal time, coordinated) of position fix

2 = Data status (A=good, V=navigation receiver warning)

3 = Current Latitude

4 = North/South in Latitude Hemisphere

5 = Current Longitude

6 = East/West in Longitude Hemisphere

7 = Speed over ground in knots

8 = (Direction of travel N:0°, E:90°, S:180°, W:270°)

9 = UT DateStamp

10 = Magnetic variation degrees (Easterly var. subtracts from true course)

11 = East/West

12 = Checksum

$GPRMC,003347.000,A,3725.3433,N,12205.7920,W,0.08,149.46,061007,,,D*70

Parts:

1: 003347.000 --> 0:33 am 47 seconds 0 milliseconds (UTC(universal time, coordinated) of position fix)

2: A --> Status is ok (Data status (A=good, V=navigation receiver warning))

3: 3725.3433 (North/South in Latitude Hemisphere)

4: N --> North (North/South)

5: 12205.7920 (Current Longitude)

6: W --> West (East/West in Longitude Hemisphere)

7: 0.08 --> 0.08 knots/second (Direction: North/West) (Speed over ground in knots)

8: 149.46 --> sth. like SouthEast (Direction of travel N:0°, E:90°, S:180°, W:270°)

9: 061007 --> 6th October, 2007 (UT(universal time) DateStamp)

10: (Magnetic variation degrees (Easterly var. subtracts from true course))