Getting heading from velocity East and Velocity North?

Another thought I had was to use velocity East and Velocity North to
determine heading. I'm no math wiz so I don't even know if this is
possible. Is it? If so where can I find the algorithm?

 

heading = atan2(Ve, Vn) in radians atan2 is a four quadrant arctangent

http://www.cplusplus.com/ref/cmath/atan2.html

 

Since most GPS units already compute the heading ( actually the track )
internally from the velocities, why bother to do it externally ?


--
Regards,

Adrian Jansen adrianjansen at internode dot on dot net
Design Engineer J & K Micro Systems
Microcomputer solutions for industrial control
Note reply address is invalid, convert address above to machine form.

 

The Garmin protocol does not give heading. Plus you would have to
download the whole track log to do it.

 

Thanks just got the same thing from an astrophysicist friend of mine.

Here is the whole thing in C

double heading = atan2(v_e, v_n); // This function returns the
angle, in radians, between -pi and pi.
heading *= 180.0 / M_PI; // Convert from radians to
degrees. Now heading is in the range [-180, 180]
if (heading < 0.0) heading += 360.0; // Get rid of negative headings.