Mbed library to handle GPS data reception and parsing
Dependents: GPS_U-blox_NEO-6M_Code
Features
- All positionning parameters are contained into a global data structure.
- Automatic nema string parsing and data structure update.
- GSA,GGA,VTG and RMC
- Convert latitude and longitude to decimal value.
- Converts latittude,longitude and altitude to ECEF coordinates.
Planed developement
- Test library for RTOS use.
- Complete the nema parsing decoders (couple of parameters are not parsed yet and not present in the data structure).
- Add conversion tool to get ENU coordinates.
Diff: defines/WGS84.h
- Revision:
- 0:0c1aa5906cef
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/defines/WGS84.h Wed Aug 06 01:37:39 2014 +0000 @@ -0,0 +1,34 @@ +/* + a the equatorial earth radius + f the "flattening" parameter ( = (a-b)/a ,the ratio of the + difference between the equatorial and polar radii to a; + this is a measure of how "elliptical" a polar cross-section + is). + + The eccentricity e of the figure of the earth is found from + + e^2 = 2f - f^2 , or e = sqrt(2f-f^2) . +*/ +//For WGS84, + +#define A 6378137.0 +#define RF 298.257224 +#define F 1/RF +#define E sqrt(2*f-f^2) + + /* + a = 6378137 meters + (1/f) = 298.257224 + +(the reciprocal of f is usually given instead of f itself, because the +reciprocal is so close to an integer) + +Given latitude (geodetic latitude, not geocentric latitude!), compute + + 1 + C = --------------------------------------------------- + sqrt( cos^2(latitude) + (1-f)^2 * sin^2(latitude) ) + +and + S = (1-f)^2 * C . +*/ \ No newline at end of file